1312220121 has 16 divisors (see below), whose sum is σ = 1820670720. Its totient is φ = 839981520.

The previous prime is 1312220093. The next prime is 1312220141. The reversal of 1312220121 is 1210222131.

It is not a de Polignac number, because 1312220121 - 2⁹ = 1312219609 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1312220121.

It is not an unprimeable number, because it can be changed into a prime (1312220141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78595 + ... + 93816.

It is an arithmetic number, because the mean of its divisors is an integer number (113791920).

Almost surely, 2^1312220121 is an apocalyptic number.

It is an amenable number.

1312220121 is a deficient number, since it is larger than the sum of its proper divisors (508450599).

1312220121 is a wasteful number, since it uses less digits than its factorization.

1312220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172516.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1312220121 is about 36224.5789623565. The cubic root of 1312220121 is about 1094.8019549673.

Adding to 1312220121 its reverse (1210222131), we get a palindrome (2522442252).

The spelling of 1312220121 in words is "one billion, three hundred twelve million, two hundred twenty thousand, one hundred twenty-one".