28657664 has 48 divisors (see below), whose sum is σ = 65520000. Its totient is φ = 12275712.

The previous prime is 28657661. The next prime is 28657687. The reversal of 28657664 is 46675682.

It is not an unprimeable number, because it can be changed into a prime (28657661) 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, 13337 + ... + 15335.

It is an arithmetic number, because the mean of its divisors is an integer number (1365000).

Almost surely, 2^28657664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28657664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32760000).

28657664 is an abundant number, since it is smaller than the sum of its proper divisors (36862336).

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

28657664 is an equidigital number, since it uses as much as digits as its factorization.

28657664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2028 (or 2008 counting only the distinct ones).

The product of its digits is 483840, while the sum is 44.

The square root of 28657664 is about 5353.2853464018. The cubic root of 28657664 is about 306.0179692411.

The spelling of 28657664 in words is "twenty-eight million, six hundred fifty-seven thousand, six hundred sixty-four".