28688980 has 24 divisors (see below), whose sum is σ = 60376680. Its totient is φ = 11450880.

The previous prime is 28688923. The next prime is 28688987. The reversal of 28688980 is 8988682.

It can be written as a sum of positive squares in 4 ways, for example, as 1628176 + 27060804 = 1276^2 + 5202^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28688987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10120 + ... + 12640.

It is an arithmetic number, because the mean of its divisors is an integer number (2515695).

Almost surely, 2^28688980 is an apocalyptic number.

28688980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28688980 is an abundant number, since it is smaller than the sum of its proper divisors (31687700).

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

28688980 is a wasteful number, since it uses less digits than its factorization.

28688980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3099 (or 3097 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 49.

The square root of 28688980 is about 5356.2094805935. The cubic root of 28688980 is about 306.1293969102.

The spelling of 28688980 in words is "twenty-eight million, six hundred eighty-eight thousand, nine hundred eighty".