100081000 has 64 divisors (see below), whose sum is σ = 239999760. Its totient is φ = 39040000.

The previous prime is 100080997. The next prime is 100081031. The reversal of 100081000 is 180001.

It can be written as a sum of positive squares in 8 ways, for example, as 10929636 + 89151364 = 3306^2 + 9442^2 .

It is a super-2 number, since 2×100081000² = 20032413122000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39780 + ... + 42220.

Almost surely, 2^100081000 is an apocalyptic number.

100081000 is a gapful number since it is divisible by the number (10) 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 100081000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119999880).

100081000 is an abundant number, since it is smaller than the sum of its proper divisors (139918760).

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

100081000 is a wasteful number, since it uses less digits than its factorization.

100081000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2503 (or 2489 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 100081000 is about 10004.0491802070. The cubic root of 100081000 is about 464.2841724378.

Subtracting from 100081000 its reverse (180001), we obtain a palindrome (99900999).

It can be divided in two parts, 1000 and 81000, that multiplied together give a square (81000000 = 9000²).

The spelling of 100081000 in words is "one hundred million, eighty-one thousand".