28509957 has 12 divisors (see below), whose sum is σ = 47064160. Its totient is φ = 16291368.

The previous prime is 28509953. The next prime is 28509959. The reversal of 28509957 is 75990582.

It is a happy number.

It is not a de Polignac number, because 28509957 - 2² = 28509953 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28509953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 226207 + ... + 226332.

Almost surely, 2^28509957 is an apocalyptic number.

It is an amenable number.

28509957 is a deficient number, since it is larger than the sum of its proper divisors (18554203).

28509957 is a wasteful number, since it uses less digits than its factorization.

28509957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452552 (or 452549 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The square root of 28509957 is about 5339.4716030709. The cubic root of 28509957 is about 305.4913052689.

It can be divided in two parts, 285099 and 57, that added together give a square (285156 = 534²).

The spelling of 28509957 in words is "twenty-eight million, five hundred nine thousand, nine hundred fifty-seven".