28257904 has 40 divisors (see below), whose sum is σ = 57049920. Its totient is φ = 13548288.

The previous prime is 28257847. The next prime is 28257907. The reversal of 28257904 is 40975282.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28257907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39502 + ... + 40210.

It is an arithmetic number, because the mean of its divisors is an integer number (1426248).

Almost surely, 2^28257904 is an apocalyptic number.

It is an amenable number.

28257904 is an abundant number, since it is smaller than the sum of its proper divisors (28792016).

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

28257904 is a wasteful number, since it uses less digits than its factorization.

28257904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817 (or 811 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 28257904 is about 5315.8164001402. The cubic root of 28257904 is about 304.5883688326.

It can be divided in two parts, 28257 and 904, that added together give a triangular number (29161 = T₂₄₁).

The spelling of 28257904 in words is "twenty-eight million, two hundred fifty-seven thousand, nine hundred four".