19928725 has 18 divisors (see below), whose sum is σ = 25247330. Its totient is φ = 15604320.

The previous prime is 19928719. The next prime is 19928773. The reversal of 19928725 is 52782991.

It can be written as a sum of positive squares in 3 ways, for example, as 4765489 + 15163236 = 2183^2 + 3894^2 .

It is not a de Polignac number, because 19928725 - 2⁵ = 19928693 is a prime.

It is a super-3 number, since 3×19928725³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 86911 + ... + 87139.

Almost surely, 2^19928725 is an apocalyptic number.

It is an amenable number.

19928725 is a deficient number, since it is larger than the sum of its proper divisors (5318605).

19928725 is an equidigital number, since it uses as much as digits as its factorization.

19928725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357 (or 293 counting only the distinct ones).

The product of its digits is 90720, while the sum is 43.

The square root of 19928725 is about 4464.1600553744. The cubic root of 19928725 is about 271.1189276626.

The spelling of 19928725 in words is "nineteen million, nine hundred twenty-eight thousand, seven hundred twenty-five".