77444603021 has 2 divisors, whose sum is σ = 77444603022. Its totient is φ = 77444603020.

The previous prime is 77444603009. The next prime is 77444603039. The reversal of 77444603021 is 12030644477.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58764547396 + 18680055625 = 242414^2 + 136675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77444603021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77444623021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38722301510 + 38722301511.

It is an arithmetic number, because the mean of its divisors is an integer number (38722301511).

Almost surely, 2^77444603021 is an apocalyptic number.

It is an amenable number.

77444603021 is a deficient number, since it is larger than the sum of its proper divisors (1).

77444603021 is an equidigital number, since it uses as much as digits as its factorization.

77444603021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 38.

The spelling of 77444603021 in words is "seventy-seven billion, four hundred forty-four million, six hundred three thousand, twenty-one".