19910120 has 32 divisors (see below), whose sum is σ = 44944200. Its totient is φ = 7938048.

The previous prime is 19910113. The next prime is 19910141. The reversal of 19910120 is 2101991.

It can be written as a sum of positive squares in 4 ways, for example, as 18130564 + 1779556 = 4258^2 + 1334^2 .

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, 15752 + ... + 16968.

Almost surely, 2^19910120 is an apocalyptic number.

19910120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19910120 is an abundant number, since it is smaller than the sum of its proper divisors (25034080).

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

19910120 is a wasteful number, since it uses less digits than its factorization.

19910120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637 (or 1633 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 19910120 is about 4462.0757501414. The cubic root of 19910120 is about 271.0345312588.

The spelling of 19910120 in words is "nineteen million, nine hundred ten thousand, one hundred twenty".