53121655 has 4 divisors (see below), whose sum is σ = 63745992. Its totient is φ = 42497320.

The previous prime is 53121637. The next prime is 53121659. The reversal of 53121655 is 55612135.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55612135 = 5 ⋅11122427.

It is not a de Polignac number, because 53121655 - 2⁵ = 53121623 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 (53121659) 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, 5312161 + ... + 5312170.

It is an arithmetic number, because the mean of its divisors is an integer number (15936498).

Almost surely, 2^53121655 is an apocalyptic number.

53121655 is a deficient number, since it is larger than the sum of its proper divisors (10624337).

53121655 is a wasteful number, since it uses less digits than its factorization.

53121655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10624336.

The product of its digits is 4500, while the sum is 28.

The square root of 53121655 is about 7288.4603998375. The cubic root of 53121655 is about 375.9157589116.

It can be divided in two parts, 5312165 and 5, that added together give a triangular number (5312170 = T₃₂₅₉).

The spelling of 53121655 in words is "fifty-three million, one hundred twenty-one thousand, six hundred fifty-five".