6657664 has 32 divisors (see below), whose sum is σ = 14287140. Its totient is φ = 3072000.

The previous prime is 6657661. The next prime is 6657667. The reversal of 6657664 is 4667566.

It is an interprime number because it is at equal distance from previous prime (6657661) and next prime (6657667).

It can be written as a sum of positive squares in 2 ways, for example, as 5198400 + 1459264 = 2280^2 + 1208^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (6657661) 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, 337 + ... + 3664.

Almost surely, 2^6657664 is an apocalyptic number.

6657664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

6657664 is an abundant number, since it is smaller than the sum of its proper divisors (7629476).

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

6657664 is a wasteful number, since it uses less digits than its factorization.

6657664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4028 (or 4016 counting only the distinct ones).

The product of its digits is 181440, while the sum is 40.

The square root of 6657664 is about 2580.2449496123. The cubic root of 6657664 is about 188.1224492761.

The spelling of 6657664 in words is "six million, six hundred fifty-seven thousand, six hundred sixty-four".