28638390 has 32 divisors (see below), whose sum is σ = 74981376. Its totient is φ = 6942560.

The previous prime is 28638383. The next prime is 28638409. The reversal of 28638390 is 9383682.

It is a congruent number.

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, 43062 + ... + 43721.

It is an arithmetic number, because the mean of its divisors is an integer number (2343168).

Almost surely, 2^28638390 is an apocalyptic number.

28638390 is an abundant number, since it is smaller than the sum of its proper divisors (46342986).

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

28638390 is a wasteful number, since it uses less digits than its factorization.

28638390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86804.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 28638390 is about 5351.4848406774. The cubic root of 28638390 is about 305.9493487012.

The spelling of 28638390 in words is "twenty-eight million, six hundred thirty-eight thousand, three hundred ninety".