666906699 has 8 divisors (see below), whose sum is σ = 893197312. Its totient is φ = 442610280.

The previous prime is 666906679. The next prime is 666906701. The reversal of 666906699 is 996609666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 666906699 - 2¹⁶ = 666841163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666906629) 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, 497767 + ... + 499104.

It is an arithmetic number, because the mean of its divisors is an integer number (111649664).

Almost surely, 2^666906699 is an apocalyptic number.

666906699 is a deficient number, since it is larger than the sum of its proper divisors (226290613).

666906699 is a wasteful number, since it uses less digits than its factorization.

666906699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997097.

The product of its (nonzero) digits is 5668704, while the sum is 57.

The square root of 666906699 is about 25824.5367625443. The cubic root of 666906699 is about 873.6852959345.

The spelling of 666906699 in words is "six hundred sixty-six million, nine hundred six thousand, six hundred ninety-nine".