53015621 has 4 divisors (see below), whose sum is σ = 55320672. Its totient is φ = 50710572.

The previous prime is 53015597. The next prime is 53015659. The reversal of 53015621 is 12651035.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 53015621 - 2¹⁴ = 52999237 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 2305027 = 53015621 / (5 + 3 + 0 + 1 + 5 + 6 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53015321) 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, 1152491 + ... + 1152536.

It is an arithmetic number, because the mean of its divisors is an integer number (13830168).

Almost surely, 2^53015621 is an apocalyptic number.

It is an amenable number.

53015621 is a deficient number, since it is larger than the sum of its proper divisors (2305051).

53015621 is a wasteful number, since it uses less digits than its factorization.

53015621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2305050.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 53015621 is about 7281.1826649247. The cubic root of 53015621 is about 375.6654755328.

Adding to 53015621 its reverse (12651035), we get a palindrome (65666656).

The spelling of 53015621 in words is "fifty-three million, fifteen thousand, six hundred twenty-one".