100640988 has 96 divisors (see below), whose sum is σ = 299980800. Its totient is φ = 28582848.

The previous prime is 100640987. The next prime is 100640989. The reversal of 100640988 is 889046001.

It is a happy number.

100640988 is a `hidden beast` number, since 1 + 0 + 0 + 640 + 9 + 8 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (100640987) and next prime (100640989).

It is a super-2 number, since 2×100640988² = 20257216931232288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100640987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 180406 + ... + 180962.

It is an arithmetic number, because the mean of its divisors is an integer number (3124800).

Almost surely, 2^100640988 is an apocalyptic number.

100640988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 100640988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149990400).

100640988 is an abundant number, since it is smaller than the sum of its proper divisors (199339812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

100640988 is a wasteful number, since it uses less digits than its factorization.

100640988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816 (or 808 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 100640988 is about 10031.9982057415. The cubic root of 100640988 is about 465.1485061568.

Adding to 100640988 its sum of digits (36), we get a square (100641024 = 10032²).

Adding to 100640988 its reverse (889046001), we get a palindrome (989686989).

The spelling of 100640988 in words is "one hundred million, six hundred forty thousand, nine hundred eighty-eight".