718385215921 has 2 divisors, whose sum is σ = 718385215922. Its totient is φ = 718385215920.

The previous prime is 718385215829. The next prime is 718385215993. The reversal of 718385215921 is 129512583817.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 434254640400 + 284130575521 = 658980^2 + 533039^2 .

It is a cyclic number.

It is not a de Polignac number, because 718385215921 - 2³⁹ = 168629402033 is a prime.

It is not a weakly prime, because it can be changed into another prime (718385215321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 359192607960 + 359192607961.

It is an arithmetic number, because the mean of its divisors is an integer number (359192607961).

Almost surely, 2^718385215921 is an apocalyptic number.

It is an amenable number.

718385215921 is a deficient number, since it is larger than the sum of its proper divisors (1).

718385215921 is an equidigital number, since it uses as much as digits as its factorization.

718385215921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1209600, while the sum is 52.

The spelling of 718385215921 in words is "seven hundred eighteen billion, three hundred eighty-five million, two hundred fifteen thousand, nine hundred twenty-one".