42312720721 has 2 divisors, whose sum is σ = 42312720722. Its totient is φ = 42312720720.

The previous prime is 42312720647. The next prime is 42312720731. The reversal of 42312720721 is 12702721324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40547460496 + 1765260225 = 201364^2 + 42015^2 .

It is a cyclic number.

It is not a de Polignac number, because 42312720721 - 2²⁵ = 42279166289 is a prime.

It is not a weakly prime, because it can be changed into another prime (42312720731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21156360360 + 21156360361.

It is an arithmetic number, because the mean of its divisors is an integer number (21156360361).

Almost surely, 2^42312720721 is an apocalyptic number.

It is an amenable number.

42312720721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42312720721 is an equidigital number, since it uses as much as digits as its factorization.

42312720721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9408, while the sum is 31.

The spelling of 42312720721 in words is "forty-two billion, three hundred twelve million, seven hundred twenty thousand, seven hundred twenty-one".