665961600 has 96 divisors (see below), whose sum is σ = 2193542640. Its totient is φ = 177587200.

The previous prime is 665961599. The next prime is 665961601. The reversal of 665961600 is 6169566.

It is an interprime number because it is at equal distance from previous prime (665961599) and next prime (665961601).

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (665961601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25086 + ... + 44285.

Almost surely, 2^665961600 is an apocalyptic number.

665961600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665961600 is an abundant number, since it is smaller than the sum of its proper divisors (1527581040).

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

665961600 is a wasteful number, since it uses less digits than its factorization.

665961600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69398 (or 69381 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 665961600 is about 25806.2318055155. The cubic root of 665961600 is about 873.2723898709.

The spelling of 665961600 in words is "six hundred sixty-five million, nine hundred sixty-one thousand, six hundred".