19911090100 has 36 divisors (see below), whose sum is σ = 47134983168. Its totient is φ = 7240396000.

The previous prime is 19911090029. The next prime is 19911090103. The reversal of 19911090100 is 109011991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19911090103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9049396 + ... + 9051595.

It is an arithmetic number, because the mean of its divisors is an integer number (1309305088).

Almost surely, 2^19911090100 is an apocalyptic number.

19911090100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19911090100 is an abundant number, since it is smaller than the sum of its proper divisors (27223893068).

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

19911090100 is a wasteful number, since it uses less digits than its factorization.

19911090100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18101016 (or 18101009 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 31.

It can be divided in two parts, 19 and 911090100, that added together give a palindrome (911090119).

The spelling of 19911090100 in words is "nineteen billion, nine hundred eleven million, ninety thousand, one hundred".