28907538 has 32 divisors (see below), whose sum is σ = 64419840. Its totient is φ = 8572560.

The previous prime is 28907521. The next prime is 28907551. The reversal of 28907538 is 83570982.

It is a self number, because there is not a number n which added to its sum of digits gives 28907538.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1558 + ... + 7761.

It is an arithmetic number, because the mean of its divisors is an integer number (2013120).

Almost surely, 2^28907538 is an apocalyptic number.

28907538 is an abundant number, since it is smaller than the sum of its proper divisors (35512302).

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

28907538 is a wasteful number, since it uses less digits than its factorization.

28907538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9382.

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 28907538 is about 5376.5730721343. The cubic root of 28907538 is about 306.9048147510.

The spelling of 28907538 in words is "twenty-eight million, nine hundred seven thousand, five hundred thirty-eight".