91672666621 has 2 divisors, whose sum is σ = 91672666622. Its totient is φ = 91672666620.

The previous prime is 91672666543. The next prime is 91672666627. The reversal of 91672666621 is 12666627619.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74982868900 + 16689797721 = 273830^2 + 129189^2 .

It is a cyclic number.

It is not a de Polignac number, because 91672666621 - 2²⁵ = 91639112189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91672666627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45836333310 + 45836333311.

It is an arithmetic number, because the mean of its divisors is an integer number (45836333311).

Almost surely, 2^91672666621 is an apocalyptic number.

It is an amenable number.

91672666621 is a deficient number, since it is larger than the sum of its proper divisors (1).

91672666621 is an equidigital number, since it uses as much as digits as its factorization.

91672666621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 52.

The spelling of 91672666621 in words is "ninety-one billion, six hundred seventy-two million, six hundred sixty-six thousand, six hundred twenty-one".