1321210013 has 4 divisors (see below), whose sum is σ = 1322868540. Its totient is φ = 1319551488.

The previous prime is 1321210003. The next prime is 1321210021. The reversal of 1321210013 is 3100121231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3100121231 = 1091 ⋅2841541.

It can be written as a sum of positive squares in 2 ways, for example, as 558235129 + 762974884 = 23627^2 + 27622^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321210013 - 2¹⁸ = 1320947869 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321210013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321210003) 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, 828068 + ... + 829661.

It is an arithmetic number, because the mean of its divisors is an integer number (330717135).

Almost surely, 2^1321210013 is an apocalyptic number.

It is an amenable number.

1321210013 is a deficient number, since it is larger than the sum of its proper divisors (1658527).

1321210013 is an equidigital number, since it uses as much as digits as its factorization.

1321210013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658526.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1321210013 is about 36348.4526905892. The cubic root of 1321210013 is about 1097.2963943433.

Adding to 1321210013 its reverse (3100121231), we get a palindrome (4421331244).

The spelling of 1321210013 in words is "one billion, three hundred twenty-one million, two hundred ten thousand, thirteen".