28931900 has 18 divisors (see below), whose sum is σ = 62782440. Its totient is φ = 11572720.

The previous prime is 28931869. The next prime is 28931911. The reversal of 28931900 is 913982.

It is a super-2 number, since 2×28931900² = 1674109675220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 144560 + ... + 144759.

Almost surely, 2^28931900 is an apocalyptic number.

28931900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28931900 is an abundant number, since it is smaller than the sum of its proper divisors (33850540).

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

28931900 is a wasteful number, since it uses less digits than its factorization.

28931900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289333 (or 289326 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 28931900 is about 5378.8381645110. The cubic root of 28931900 is about 306.9910058303.

The spelling of 28931900 in words is "twenty-eight million, nine hundred thirty-one thousand, nine hundred".