28661900 has 18 divisors (see below), whose sum is σ = 62196540. Its totient is φ = 11464720.

The previous prime is 28661891. The next prime is 28661903. The reversal of 28661900 is 916682.

It is a super-2 number, since 2×28661900² = 1643009023220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28661903) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 143210 + ... + 143409.

Almost surely, 2^28661900 is an apocalyptic number.

28661900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28661900 is an abundant number, since it is smaller than the sum of its proper divisors (33534640).

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

28661900 is a wasteful number, since it uses less digits than its factorization.

28661900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286633 (or 286626 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 28661900 is about 5353.6809766739. The cubic root of 28661900 is about 306.0330463976.

The spelling of 28661900 in words is "twenty-eight million, six hundred sixty-one thousand, nine hundred".