668474185651 has 2 divisors, whose sum is σ = 668474185652. Its totient is φ = 668474185650.

The previous prime is 668474185591. The next prime is 668474185697. The reversal of 668474185651 is 156581474866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 668474185651 - 2²¹ = 668472088499 is a prime.

It is a super-2 number, since 2×668474185651² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 668474185651.

It is not a weakly prime, because it can be changed into another prime (668474185151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334237092825 + 334237092826.

It is an arithmetic number, because the mean of its divisors is an integer number (334237092826).

Almost surely, 2^668474185651 is an apocalyptic number.

668474185651 is a deficient number, since it is larger than the sum of its proper divisors (1).

668474185651 is an equidigital number, since it uses as much as digits as its factorization.

668474185651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38707200, while the sum is 61.

The spelling of 668474185651 in words is "six hundred sixty-eight billion, four hundred seventy-four million, one hundred eighty-five thousand, six hundred fifty-one".