668697961 has 4 divisors (see below), whose sum is σ = 668800000. Its totient is φ = 668595924.

The previous prime is 668697947. The next prime is 668697973. The reversal of 668697961 is 169796866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668697961 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668697896 and 668697905.

It is not an unprimeable number, because it can be changed into a prime (668697061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40461 + ... + 54538.

It is an arithmetic number, because the mean of its divisors is an integer number (167200000).

Almost surely, 2^668697961 is an apocalyptic number.

It is an amenable number.

668697961 is a deficient number, since it is larger than the sum of its proper divisors (102039).

668697961 is an equidigital number, since it uses as much as digits as its factorization.

668697961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102038.

The product of its digits is 5878656, while the sum is 58.

The square root of 668697961 is about 25859.1949023940. The cubic root of 668697961 is about 874.4668146500.

The spelling of 668697961 in words is "six hundred sixty-eight million, six hundred ninety-seven thousand, nine hundred sixty-one".