31540325521 has 2 divisors, whose sum is σ = 31540325522. Its totient is φ = 31540325520.

The previous prime is 31540325519. The next prime is 31540325561. The reversal of 31540325521 is 12552304513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29003793025 + 2536532496 = 170305^2 + 50364^2 .

It is a cyclic number.

It is not a de Polignac number, because 31540325521 - 2¹ = 31540325519 is a prime.

Together with 31540325519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31540325561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770162760 + 15770162761.

It is an arithmetic number, because the mean of its divisors is an integer number (15770162761).

Almost surely, 2^31540325521 is an apocalyptic number.

It is an amenable number.

31540325521 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540325521 is an equidigital number, since it uses as much as digits as its factorization.

31540325521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 31.

The spelling of 31540325521 in words is "thirty-one billion, five hundred forty million, three hundred twenty-five thousand, five hundred twenty-one".