28087236 has 30 divisors (see below), whose sum is σ = 73426430. Its totient is φ = 9362304.

The previous prime is 28087219. The next prime is 28087237. The reversal of 28087236 is 63278082.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17589636 + 10497600 = 4194^2 + 3240^2 .

It is a super-2 number, since 2×28087236² = 1577785652239392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 28087236.

It is not an unprimeable number, because it can be changed into a prime (28087237) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 43021 + ... + 43668.

Almost surely, 2^28087236 is an apocalyptic number.

It is an amenable number.

28087236 is an abundant number, since it is smaller than the sum of its proper divisors (45339194).

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

28087236 is a wasteful number, since it uses less digits than its factorization.

28087236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86705 (or 86694 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 28087236 is about 5299.7392388683. The cubic root of 28087236 is about 303.9739272422.

The spelling of 28087236 in words is "twenty-eight million, eighty-seven thousand, two hundred thirty-six".