667216076621 has 2 divisors, whose sum is σ = 667216076622. Its totient is φ = 667216076620.

The previous prime is 667216076587. The next prime is 667216076641. The reversal of 667216076621 is 126670612766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 406285134025 + 260930942596 = 637405^2 + 510814^2 .

It is a cyclic number.

It is not a de Polignac number, because 667216076621 - 2¹⁸ = 667215814477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 667216076621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667216076641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333608038310 + 333608038311.

It is an arithmetic number, because the mean of its divisors is an integer number (333608038311).

Almost surely, 2^667216076621 is an apocalyptic number.

It is an amenable number.

667216076621 is a deficient number, since it is larger than the sum of its proper divisors (1).

667216076621 is an equidigital number, since it uses as much as digits as its factorization.

667216076621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1524096, while the sum is 50.

The spelling of 667216076621 in words is "six hundred sixty-seven billion, two hundred sixteen million, seventy-six thousand, six hundred twenty-one".