28938920 has 16 divisors (see below), whose sum is σ = 65112660. Its totient is φ = 11575552.

The previous prime is 28938911. The next prime is 28938937. The reversal of 28938920 is 2983982.

It can be written as a sum of positive squares in 2 ways, for example, as 28536964 + 401956 = 5342^2 + 634^2 .

It is a super-2 number, since 2×28938920² = 1674922181532800, which contains 22 as substring.

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, 361697 + ... + 361776.

Almost surely, 2^28938920 is an apocalyptic number.

28938920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28938920 is an abundant number, since it is smaller than the sum of its proper divisors (36173740).

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

28938920 is a wasteful number, since it uses less digits than its factorization.

28938920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723484 (or 723480 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 28938920 is about 5379.4906822115. The cubic root of 28938920 is about 307.0158331268.

The spelling of 28938920 in words is "twenty-eight million, nine hundred thirty-eight thousand, nine hundred twenty".