15138728 has 16 divisors (see below), whose sum is σ = 30965760. Its totient is φ = 6881200.

The previous prime is 15138719. The next prime is 15138731. The reversal of 15138728 is 82783151.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85928 + ... + 86103.

It is an arithmetic number, because the mean of its divisors is an integer number (1935360).

Almost surely, 2^15138728 is an apocalyptic number.

It is an amenable number.

15138728 is an abundant number, since it is smaller than the sum of its proper divisors (15827032).

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

15138728 is a wasteful number, since it uses less digits than its factorization.

15138728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172048 (or 172044 counting only the distinct ones).

The product of its digits is 13440, while the sum is 35.

The square root of 15138728 is about 3890.8518347529. The cubic root of 15138728 is about 247.3791703508.

The spelling of 15138728 in words is "fifteen million, one hundred thirty-eight thousand, seven hundred twenty-eight".