2121331613 has 2 divisors, whose sum is σ = 2121331614. Its totient is φ = 2121331612.

The previous prime is 2121331609. The next prime is 2121331631. The reversal of 2121331613 is 3161331212.

Together with next prime (2121331631) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1316020729 + 805310884 = 36277^2 + 28378^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121331613 - 2² = 2121331609 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121321613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060665806 + 1060665807.

It is an arithmetic number, because the mean of its divisors is an integer number (1060665807).

Almost surely, 2^2121331613 is an apocalyptic number.

It is an amenable number.

2121331613 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121331613 is an equidigital number, since it uses as much as digits as its factorization.

2121331613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 23.

The square root of 2121331613 is about 46057.9158560176. The cubic root of 2121331613 is about 1284.9005687471.

Adding to 2121331613 its reverse (3161331212), we get a palindrome (5282662825).

The spelling of 2121331613 in words is "two billion, one hundred twenty-one million, three hundred thirty-one thousand, six hundred thirteen".