28404978 has 32 divisors (see below), whose sum is σ = 67167360. Its totient is φ = 7835520.

The previous prime is 28404919. The next prime is 28404989. The reversal of 28404978 is 87940482.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 10443 + ... + 12878.

It is an arithmetic number, because the mean of its divisors is an integer number (2098980).

Almost surely, 2^28404978 is an apocalyptic number.

28404978 is an abundant number, since it is smaller than the sum of its proper divisors (38762382).

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

28404978 is a wasteful number, since it uses less digits than its factorization.

28404978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23362.

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 28404978 is about 5329.6320698525. The cubic root of 28404978 is about 305.1158853732.

The spelling of 28404978 in words is "twenty-eight million, four hundred four thousand, nine hundred seventy-eight".