28639684 has 6 divisors (see below), whose sum is σ = 50119454. Its totient is φ = 14319840.

The previous prime is 28639649. The next prime is 28639687. The reversal of 28639684 is 48693682.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21827584 + 6812100 = 4672^2 + 2610^2 .

It is not an unprimeable number, because it can be changed into a prime (28639687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3579957 + ... + 3579964.

Almost surely, 2^28639684 is an apocalyptic number.

It is an amenable number.

28639684 is a deficient number, since it is larger than the sum of its proper divisors (21479770).

28639684 is a wasteful number, since it uses less digits than its factorization.

28639684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7159925 (or 7159923 counting only the distinct ones).

The product of its digits is 497664, while the sum is 46.

The square root of 28639684 is about 5351.6057403363. The cubic root of 28639684 is about 305.9539566475.

The spelling of 28639684 in words is "twenty-eight million, six hundred thirty-nine thousand, six hundred eighty-four".