100991056 has 40 divisors (see below), whose sum is σ = 207478784. Its totient is φ = 47537280.

The previous prime is 100991041. The next prime is 100991063. The reversal of 100991056 is 650199001.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15601 + ... + 21103.

Almost surely, 2^100991056 is an apocalyptic number.

100991056 is a gapful number since it is divisible by the number (16) 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 100991056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103739392).

100991056 is an abundant number, since it is smaller than the sum of its proper divisors (106487728).

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

100991056 is a wasteful number, since it uses less digits than its factorization.

100991056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5579 (or 5573 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 100991056 is about 10049.4306306377. The cubic root of 100991056 is about 465.6872037432.

The spelling of 100991056 in words is "one hundred million, nine hundred ninety-one thousand, fifty-six".