19901012100 has 72 divisors (see below), whose sum is σ = 58524254208. Its totient is φ = 5219932800.

The previous prime is 19901012071. The next prime is 19901012101. The reversal of 19901012100 is 121010991.

It is not an unprimeable number, because it can be changed into a prime (19901012101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 525444 + ... + 562043.

It is an arithmetic number, because the mean of its divisors is an integer number (812836864).

Almost surely, 2^19901012100 is an apocalyptic number.

19901012100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19901012100 is an abundant number, since it is smaller than the sum of its proper divisors (38623242108).

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

19901012100 is a wasteful number, since it uses less digits than its factorization.

19901012100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1087565 (or 1087558 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 24.

The spelling of 19901012100 in words is "nineteen billion, nine hundred one million, twelve thousand, one hundred".