665700640 has 48 divisors (see below), whose sum is σ = 1715696640. Its totient is φ = 242072320.

The previous prime is 665700613. The next prime is 665700647. The reversal of 665700640 is 46007566.

It is a junction number, because it is equal to n+sod(n) for n = 665700596 and 665700605.

It is not an unprimeable number, because it can be changed into a prime (665700647) 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, 187360 + ... + 190879.

It is an arithmetic number, because the mean of its divisors is an integer number (35743680).

Almost surely, 2^665700640 is an apocalyptic number.

It is an amenable number.

665700640 is an abundant number, since it is smaller than the sum of its proper divisors (1049996000).

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

665700640 is a wasteful number, since it uses less digits than its factorization.

665700640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378265 (or 378257 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 665700640 is about 25801.1751670345. The cubic root of 665700640 is about 873.1583097519.

The spelling of 665700640 in words is "six hundred sixty-five million, seven hundred thousand, six hundred forty".