666631499 has 4 divisors (see below), whose sum is σ = 666900336. Its totient is φ = 666362664.

The previous prime is 666631487. The next prime is 666631519. The reversal of 666631499 is 994136666.

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 666631499 - 2⁸ = 666631243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666631699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130664 + ... + 135669.

It is an arithmetic number, because the mean of its divisors is an integer number (166725084).

Almost surely, 2^666631499 is an apocalyptic number.

666631499 is a deficient number, since it is larger than the sum of its proper divisors (268837).

666631499 is a wasteful number, since it uses less digits than its factorization.

666631499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268836.

The product of its digits is 1259712, while the sum is 50.

The square root of 666631499 is about 25819.2079467981. The cubic root of 666631499 is about 873.5651035729.

The spelling of 666631499 in words is "six hundred sixty-six million, six hundred thirty-one thousand, four hundred ninety-nine".