28972880 has 20 divisors (see below), whose sum is σ = 67362132. Its totient is φ = 11589120.

The previous prime is 28972873. The next prime is 28972883. The reversal of 28972880 is 8827982.

It can be written as a sum of positive squares in 2 ways, for example, as 3125824 + 25847056 = 1768^2 + 5084^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28972883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181001 + ... + 181160.

Almost surely, 2^28972880 is an apocalyptic number.

28972880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28972880 is an abundant number, since it is smaller than the sum of its proper divisors (38389252).

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

28972880 is a wasteful number, since it uses less digits than its factorization.

28972880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362174 (or 362168 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The square root of 28972880 is about 5382.6461893756. The cubic root of 28972880 is about 307.1358811674.

The spelling of 28972880 in words is "twenty-eight million, nine hundred seventy-two thousand, eight hundred eighty".