668972977819 has 2 divisors, whose sum is σ = 668972977820. Its totient is φ = 668972977818.

The previous prime is 668972977801. The next prime is 668972977847. The reversal of 668972977819 is 918779279866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668972977819 - 2¹¹ = 668972975771 is a prime.

It is a super-2 number, since 2×668972977819² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (668972977019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334486488909 + 334486488910.

It is an arithmetic number, because the mean of its divisors is an integer number (334486488910).

Almost surely, 2^668972977819 is an apocalyptic number.

668972977819 is a deficient number, since it is larger than the sum of its proper divisors (1).

668972977819 is an equidigital number, since it uses as much as digits as its factorization.

668972977819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152216576, while the sum is 79.

The spelling of 668972977819 in words is "six hundred sixty-eight billion, nine hundred seventy-two million, nine hundred seventy-seven thousand, eight hundred nineteen".