52491521 has 4 divisors (see below), whose sum is σ = 53771844. Its totient is φ = 51211200.

The previous prime is 52491511. The next prime is 52491541. The reversal of 52491521 is 12519425.

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 18105025 + 34386496 = 4255^2 + 5864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-52491521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (52491511) 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, 640100 + ... + 640181.

It is an arithmetic number, because the mean of its divisors is an integer number (13442961).

Almost surely, 2^52491521 is an apocalyptic number.

It is an amenable number.

52491521 is a deficient number, since it is larger than the sum of its proper divisors (1280323).

52491521 is a wasteful number, since it uses less digits than its factorization.

52491521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280322.

The product of its digits is 3600, while the sum is 29.

The square root of 52491521 is about 7245.1032428807. The cubic root of 52491521 is about 374.4234601331.

The spelling of 52491521 in words is "fifty-two million, four hundred ninety-one thousand, five hundred twenty-one".