28931636 has 6 divisors (see below), whose sum is σ = 50630370. Its totient is φ = 14465816.

The previous prime is 28931621. The next prime is 28931641. The reversal of 28931636 is 63613982.

It can be written as a sum of positive squares in only one way, i.e., 28622500 + 309136 = 5350^2 + 556^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28931636.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3616451 + ... + 3616458.

It is an arithmetic number, because the mean of its divisors is an integer number (8438395).

Almost surely, 2^28931636 is an apocalyptic number.

It is an amenable number.

28931636 is a deficient number, since it is larger than the sum of its proper divisors (21698734).

28931636 is a wasteful number, since it uses less digits than its factorization.

28931636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7232913 (or 7232911 counting only the distinct ones).

The product of its digits is 46656, while the sum is 38.

The square root of 28931636 is about 5378.8136238394. The cubic root of 28931636 is about 306.9900720758.

The spelling of 28931636 in words is "twenty-eight million, nine hundred thirty-one thousand, six hundred thirty-six".