1313656121 has 4 divisors (see below), whose sum is σ = 1314103332. Its totient is φ = 1313208912.

The previous prime is 1313656117. The next prime is 1313656139. The reversal of 1313656121 is 1216563131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 101223721 + 1212432400 = 10061^2 + 34820^2 .

It is a cyclic number.

It is not a de Polignac number, because 1313656121 - 2² = 1313656117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1313656111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219170 + ... + 225083.

It is an arithmetic number, because the mean of its divisors is an integer number (328525833).

Almost surely, 2^1313656121 is an apocalyptic number.

It is an amenable number.

1313656121 is a deficient number, since it is larger than the sum of its proper divisors (447211).

1313656121 is an equidigital number, since it uses as much as digits as its factorization.

1313656121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447210.

The product of its digits is 3240, while the sum is 29.

The square root of 1313656121 is about 36244.3943389871. The cubic root of 1313656121 is about 1095.2011670743.

The spelling of 1313656121 in words is "one billion, three hundred thirteen million, six hundred fifty-six thousand, one hundred twenty-one".