28387664 has 20 divisors (see below), whose sum is σ = 55154580. Its totient is φ = 14154240.

The previous prime is 28387663. The next prime is 28387679. The reversal of 28387664 is 46678382.

It can be written as a sum of positive squares in 2 ways, for example, as 8065600 + 20322064 = 2840^2 + 4508^2 .

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28387663) 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, 3944 + ... + 8504.

It is an arithmetic number, because the mean of its divisors is an integer number (2757729).

Almost surely, 2^28387664 is an apocalyptic number.

It is an amenable number.

28387664 is a deficient number, since it is larger than the sum of its proper divisors (26766916).

28387664 is a wasteful number, since it uses less digits than its factorization.

28387664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4958 (or 4952 counting only the distinct ones).

The product of its digits is 387072, while the sum is 44.

The square root of 28387664 is about 5328.0075075022. The cubic root of 28387664 is about 305.0538792211.

The spelling of 28387664 in words is "twenty-eight million, three hundred eighty-seven thousand, six hundred sixty-four".