100531440 has 60 divisors (see below), whose sum is σ = 337620504. Its totient is φ = 26808192.

The previous prime is 100531433. The next prime is 100531441. The reversal of 100531440 is 44135001.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100531441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69094 + ... + 70533.

Almost surely, 2^100531440 is an apocalyptic number.

100531440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100531440 is an abundant number, since it is smaller than the sum of its proper divisors (237089064).

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

100531440 is a wasteful number, since it uses less digits than its factorization.

100531440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139646 (or 139637 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 100531440 is about 10026.5367899390. The cubic root of 100531440 is about 464.9796730622.

Adding to 100531440 its reverse (44135001), we get a palindrome (144666441).

The spelling of 100531440 in words is "one hundred million, five hundred thirty-one thousand, four hundred forty".