28591520 has 24 divisors (see below), whose sum is σ = 67547844. Its totient is φ = 11436544.

The previous prime is 28591483. The next prime is 28591529. The reversal of 28591520 is 2519582.

It can be written as a sum of positive squares in 2 ways, for example, as 27583504 + 1008016 = 5252^2 + 1004^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (28591529) 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, 89189 + ... + 89508.

Almost surely, 2^28591520 is an apocalyptic number.

28591520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28591520 is an abundant number, since it is smaller than the sum of its proper divisors (38956324).

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

28591520 is a wasteful number, since it uses less digits than its factorization.

28591520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178712 (or 178704 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 28591520 is about 5347.1038890225. The cubic root of 28591520 is about 305.7823505328.

The spelling of 28591520 in words is "twenty-eight million, five hundred ninety-one thousand, five hundred twenty".