660690986 has 4 divisors (see below), whose sum is σ = 991036482. Its totient is φ = 330345492.

The previous prime is 660690929. The next prime is 660691013. The reversal of 660690986 is 689096066.

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

It can be written as a sum of positive squares in only one way, i.e., 659513761 + 1177225 = 25681^2 + 1085^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165172745 + ... + 165172748.

Almost surely, 2^660690986 is an apocalyptic number.

660690986 is a deficient number, since it is larger than the sum of its proper divisors (330345496).

660690986 is a wasteful number, since it uses less digits than its factorization.

660690986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330345495.

The product of its (nonzero) digits is 839808, while the sum is 50.

The square root of 660690986 is about 25703.9099360389. The cubic root of 660690986 is about 870.9625081020.

The spelling of 660690986 in words is "six hundred sixty million, six hundred ninety thousand, nine hundred eighty-six".