666732215 has 4 divisors (see below), whose sum is σ = 800078664. Its totient is φ = 533385768.

The previous prime is 666732179. The next prime is 666732239. The reversal of 666732215 is 512237666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666732215 - 2¹² = 666728119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66673217 + ... + 66673226.

It is an arithmetic number, because the mean of its divisors is an integer number (200019666).

Almost surely, 2^666732215 is an apocalyptic number.

666732215 is a deficient number, since it is larger than the sum of its proper divisors (133346449).

666732215 is a wasteful number, since it uses less digits than its factorization.

666732215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133346448.

The product of its digits is 90720, while the sum is 38.

The square root of 666732215 is about 25821.1582815334. The cubic root of 666732215 is about 873.6090946697.

The spelling of 666732215 in words is "six hundred sixty-six million, seven hundred thirty-two thousand, two hundred fifteen".