1321540631525 has 12 divisors (see below), whose sum is σ = 1638795156900. Its totient is φ = 1057177812480.

The previous prime is 1321540631503. The next prime is 1321540631531. The reversal of 1321540631525 is 5251360451231.

It can be written as a sum of positive squares in 6 ways, for example, as 66206377636 + 1255334253889 = 257306^2 + 1120417^2 .

It is not a de Polignac number, because 1321540631525 - 2⁸ = 1321540631269 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 870860 + ... + 1844309.

It is an arithmetic number, because the mean of its divisors is an integer number (136566263075).

Almost surely, 2^{1321540631525} is an apocalyptic number.

It is an amenable number.

1321540631525 is a deficient number, since it is larger than the sum of its proper divisors (317254525375).

1321540631525 is a wasteful number, since it uses less digits than its factorization.

1321540631525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2734648 (or 2734643 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 38.

The spelling of 1321540631525 in words is "one trillion, three hundred twenty-one billion, five hundred forty million, six hundred thirty-one thousand, five hundred twenty-five".