53613661 has 4 divisors (see below), whose sum is σ = 53693532. Its totient is φ = 53533792.

The previous prime is 53613653. The next prime is 53613671. The reversal of 53613661 is 16631635.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16631635 = 5 ⋅3326327.

It can be written as a sum of positive squares in 2 ways, for example, as 39879225 + 13734436 = 6315^2 + 3706^2 .

It is a cyclic number.

It is not a de Polignac number, because 53613661 - 2³ = 53613653 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 (53613671) 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, 38920 + ... + 40273.

It is an arithmetic number, because the mean of its divisors is an integer number (13423383).

Almost surely, 2^53613661 is an apocalyptic number.

It is an amenable number.

53613661 is a deficient number, since it is larger than the sum of its proper divisors (79871).

53613661 is an equidigital number, since it uses as much as digits as its factorization.

53613661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79870.

The product of its digits is 9720, while the sum is 31.

The square root of 53613661 is about 7322.1350028527. The cubic root of 53613661 is about 377.0727555315.

The spelling of 53613661 in words is "fifty-three million, six hundred thirteen thousand, six hundred sixty-one".