3121600121521 has 12 divisors (see below), whose sum is σ = 3638383234740. Its totient is φ = 2670400531680.

The previous prime is 3121600121483. The next prime is 3121600121551. The reversal of 3121600121521 is 1251210061213.

It can be written as a sum of positive squares in 2 ways, for example, as 2596091115121 + 525509006400 = 1611239^2 + 724920^2 .

It is not a de Polignac number, because 3121600121521 - 2³⁹ = 2571844307633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3121600121551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62554750 + ... + 62604631.

It is an arithmetic number, because the mean of its divisors is an integer number (303198602895).

Almost surely, 2^{3121600121521} is an apocalyptic number.

It is an amenable number.

3121600121521 is a deficient number, since it is larger than the sum of its proper divisors (516783113219).

3121600121521 is a wasteful number, since it uses less digits than its factorization.

3121600121521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125159904 (or 125159897 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

Adding to 3121600121521 its reverse (1251210061213), we get a palindrome (4372810182734).

The spelling of 3121600121521 in words is "three trillion, one hundred twenty-one billion, six hundred million, one hundred twenty-one thousand, five hundred twenty-one".