42665425921 has 2 divisors, whose sum is σ = 42665425922. Its totient is φ = 42665425920.

The previous prime is 42665425909. The next prime is 42665425949. The reversal of 42665425921 is 12952456624.

42665425921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40064425921 + 2601000000 = 200161^2 + 51000^2 .

It is a cyclic number.

It is not a de Polignac number, because 42665425921 - 2²¹ = 42663328769 is a prime.

It is not a weakly prime, because it can be changed into another prime (42665425981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21332712960 + 21332712961.

It is an arithmetic number, because the mean of its divisors is an integer number (21332712961).

Almost surely, 2^42665425921 is an apocalyptic number.

It is an amenable number.

42665425921 is a deficient number, since it is larger than the sum of its proper divisors (1).

42665425921 is an equidigital number, since it uses as much as digits as its factorization.

42665425921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1036800, while the sum is 46.

The spelling of 42665425921 in words is "forty-two billion, six hundred sixty-five million, four hundred twenty-five thousand, nine hundred twenty-one".