19928640 has 56 divisors (see below), whose sum is σ = 63276480. Its totient is φ = 5314048.

The previous prime is 19928633. The next prime is 19928653. The reversal of 19928640 is 4682991.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9420 + ... + 11339.

Almost surely, 2^19928640 is an apocalyptic number.

19928640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19928640 is an abundant number, since it is smaller than the sum of its proper divisors (43347840).

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

19928640 is a wasteful number, since it uses less digits than its factorization.

19928640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20779 (or 20769 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 19928640 is about 4464.1505350962. The cubic root of 19928640 is about 271.1185422033.

The spelling of 19928640 in words is "nineteen million, nine hundred twenty-eight thousand, six hundred forty".