53565721 has 16 divisors (see below), whose sum is σ = 60717888. Its totient is φ = 46828800.

The previous prime is 53565719. The next prime is 53565727. The reversal of 53565721 is 12756535.

It is a cyclic number.

It is not a de Polignac number, because 53565721 - 2¹ = 53565719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (53565727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32110 + ... + 33736.

It is an arithmetic number, because the mean of its divisors is an integer number (3794868).

Almost surely, 2^53565721 is an apocalyptic number.

It is an amenable number.

53565721 is a deficient number, since it is larger than the sum of its proper divisors (7152167).

53565721 is a wasteful number, since it uses less digits than its factorization.

53565721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752.

The product of its digits is 31500, while the sum is 34.

The square root of 53565721 is about 7318.8606353721. The cubic root of 53565721 is about 376.9603323282.

The spelling of 53565721 in words is "fifty-three million, five hundred sixty-five thousand, seven hundred twenty-one".