28664240 has 40 divisors (see below), whose sum is σ = 72705168. Its totient is φ = 10423040.

The previous prime is 28664239. The next prime is 28664249. The reversal of 28664240 is 4246682.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 28664197 and 28664206.

It is not an unprimeable number, because it can be changed into a prime (28664249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15407 + ... + 17166.

Almost surely, 2^28664240 is an apocalyptic number.

28664240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28664240 is an abundant number, since it is smaller than the sum of its proper divisors (44040928).

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

28664240 is a wasteful number, since it uses less digits than its factorization.

28664240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32597 (or 32591 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 28664240 is about 5353.8995134388. The cubic root of 28664240 is about 306.0413745014.

It can be divided in two parts, 286642 and 40, that added together give a palindrome (286682).

The spelling of 28664240 in words is "twenty-eight million, six hundred sixty-four thousand, two hundred forty".