665972515 has 32 divisors (see below), whose sum is σ = 908712000. Its totient is φ = 464486400.

The previous prime is 665972459. The next prime is 665972539. The reversal of 665972515 is 515279566.

It is a de Polignac number, because none of the positive numbers 2^k-665972515 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 553915 + ... + 555115.

It is an arithmetic number, because the mean of its divisors is an integer number (28397250).

Almost surely, 2^665972515 is an apocalyptic number.

665972515 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

665972515 is a deficient number, since it is larger than the sum of its proper divisors (242739485).

665972515 is a wasteful number, since it uses less digits than its factorization.

665972515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687.

The product of its digits is 567000, while the sum is 46.

The square root of 665972515 is about 25806.4432845753. The cubic root of 665972515 is about 873.2771607747.

The spelling of 665972515 in words is "six hundred sixty-five million, nine hundred seventy-two thousand, five hundred fifteen".