53121613 has 4 divisors (see below), whose sum is σ = 53509500. Its totient is φ = 52733728.

The previous prime is 53121581. The next prime is 53121623. The reversal of 53121613 is 31612135.

It is a happy number.

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 33212169 + 19909444 = 5763^2 + 4462^2 .

It is a cyclic number.

It is not a de Polignac number, because 53121613 - 2⁵ = 53121581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53121623) 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, 193738 + ... + 194011.

It is an arithmetic number, because the mean of its divisors is an integer number (13377375).

Almost surely, 2^53121613 is an apocalyptic number.

It is an amenable number.

53121613 is a deficient number, since it is larger than the sum of its proper divisors (387887).

53121613 is a wasteful number, since it uses less digits than its factorization.

53121613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387886.

The product of its digits is 540, while the sum is 22.

The square root of 53121613 is about 7288.4575185700. The cubic root of 53121613 is about 375.9156598405.

Adding to 53121613 its reverse (31612135), we get a palindrome (84733748).

The spelling of 53121613 in words is "fifty-three million, one hundred twenty-one thousand, six hundred thirteen".