77173045476221 has 2 divisors, whose sum is σ = 77173045476222. Its totient is φ = 77173045476220.

The previous prime is 77173045476161. The next prime is 77173045476227. The reversal of 77173045476221 is 12267454037177.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56514475147321 + 20658570328900 = 7517611^2 + 4545170^2 .

It is an emirp because it is prime and its reverse (12267454037177) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77173045476221 - 2²⁶ = 77172978367357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77173045476227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38586522738110 + 38586522738111.

It is an arithmetic number, because the mean of its divisors is an integer number (38586522738111).

Almost surely, 2^{77173045476221} is an apocalyptic number.

It is an amenable number.

77173045476221 is a deficient number, since it is larger than the sum of its proper divisors (1).

77173045476221 is an equidigital number, since it uses as much as digits as its factorization.

77173045476221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13829760, while the sum is 56.

The spelling of 77173045476221 in words is "seventy-seven trillion, one hundred seventy-three billion, forty-five million, four hundred seventy-six thousand, two hundred twenty-one".