7681664 has 16 divisors (see below), whose sum is σ = 15303570. Its totient is φ = 3840768.

The previous prime is 7681657. The next prime is 7681691. The reversal of 7681664 is 4661867.

It can be written as a sum of positive squares in only one way, i.e., 5721664 + 1960000 = 2392^2 + 1400^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 29879 + ... + 30134.

Almost surely, 2^7681664 is an apocalyptic number.

It is an amenable number.

7681664 is a deficient number, since it is larger than the sum of its proper divisors (7621906).

7681664 is an equidigital number, since it uses as much as digits as its factorization.

7681664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60027 (or 60015 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 7681664 is about 2771.5814979899. The cubic root of 7681664 is about 197.3112141428.

The spelling of 7681664 in words is "seven million, six hundred eighty-one thousand, six hundred sixty-four".