1312402121 has 4 divisors (see below), whose sum is σ = 1312476612. Its totient is φ = 1312327632.

The previous prime is 1312402051. The next prime is 1312402141. The reversal of 1312402121 is 1212042131.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 904806400 + 407595721 = 30080^2 + 20189^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312402121 - 2¹⁸ = 1312139977 is a prime.

It is a Duffinian number.

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 1312402121.

It is not an unprimeable number, because it can be changed into a prime (1312402141) 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, 5651 + ... + 51543.

It is an arithmetic number, because the mean of its divisors is an integer number (328119153).

Almost surely, 2^1312402121 is an apocalyptic number.

It is an amenable number.

1312402121 is a deficient number, since it is larger than the sum of its proper divisors (74491).

1312402121 is an equidigital number, since it uses as much as digits as its factorization.

1312402121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74490.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1312402121 is about 36227.0909817501. The cubic root of 1312402121 is about 1094.8525675999.

Adding to 1312402121 its reverse (1212042131), we get a palindrome (2524444252).

The spelling of 1312402121 in words is "one billion, three hundred twelve million, four hundred two thousand, one hundred twenty-one".