6642864 has 40 divisors (see below), whose sum is σ = 19068720. Its totient is φ = 2214144.

The previous prime is 6642863. The next prime is 6642877. The reversal of 6642864 is 4682466.

It is a happy number.

6642864 is a `hidden beast` number, since 6 + 642 + 8 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (6642863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7257 + ... + 8120.

It is an arithmetic number, because the mean of its divisors is an integer number (476718).

Almost surely, 2^6642864 is an apocalyptic number.

It is an amenable number.

6642864 is an abundant number, since it is smaller than the sum of its proper divisors (12425856).

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

6642864 is a wasteful number, since it uses less digits than its factorization.

6642864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15394 (or 15382 counting only the distinct ones).

The product of its digits is 55296, while the sum is 36.

The square root of 6642864 is about 2577.3754092099. The cubic root of 6642864 is about 187.9829469970.

The spelling of 6642864 in words is "six million, six hundred forty-two thousand, eight hundred sixty-four".