66799515 has 16 divisors (see below), whose sum is σ = 107059968. Its totient is φ = 35566176.

The previous prime is 66799493. The next prime is 66799547. The reversal of 66799515 is 51599766.

It is not a de Polignac number, because 66799515 - 2¹² = 66795419 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6264 + ... + 13146.

It is an arithmetic number, because the mean of its divisors is an integer number (6691248).

Almost surely, 2^66799515 is an apocalyptic number.

66799515 is a deficient number, since it is larger than the sum of its proper divisors (40260453).

66799515 is a wasteful number, since it uses less digits than its factorization.

66799515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7538.

The product of its digits is 510300, while the sum is 48.

The square root of 66799515 is about 8173.0970262196. The cubic root of 66799515 is about 405.7492911307.

The spelling of 66799515 in words is "sixty-six million, seven hundred ninety-nine thousand, five hundred fifteen".