28438864 has 20 divisors (see below), whose sum is σ = 55204180. Its totient is φ = 14192640.

The previous prime is 28438853. The next prime is 28438889. The reversal of 28438864 is 46883482.

It can be written as a sum of positive squares in 2 ways, for example, as 10291264 + 18147600 = 3208^2 + 4260^2 .

It is a super-2 number, since 2×28438864² = 1617537971220992, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28438864.

It is a congruent number.

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, 9232 + ... + 11920.

It is an arithmetic number, because the mean of its divisors is an integer number (2760209).

Almost surely, 2^28438864 is an apocalyptic number.

It is an amenable number.

28438864 is a deficient number, since it is larger than the sum of its proper divisors (26765316).

28438864 is a wasteful number, since it uses less digits than its factorization.

28438864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3358 (or 3352 counting only the distinct ones).

The product of its digits is 294912, while the sum is 43.

The square root of 28438864 is about 5332.8101410045. The cubic root of 28438864 is about 305.2371674975.

The spelling of 28438864 in words is "twenty-eight million, four hundred thirty-eight thousand, eight hundred sixty-four".