56121521 has 4 divisors (see below), whose sum is σ = 56832000. Its totient is φ = 55411044.

The previous prime is 56121511. The next prime is 56121523. The reversal of 56121521 is 12512165.

It is a happy number.

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 56121521 - 2¹⁰ = 56120497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56121523) 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, 355121 + ... + 355278.

It is an arithmetic number, because the mean of its divisors is an integer number (14208000).

Almost surely, 2^56121521 is an apocalyptic number.

It is an amenable number.

56121521 is a deficient number, since it is larger than the sum of its proper divisors (710479).

56121521 is an equidigital number, since it uses as much as digits as its factorization.

56121521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710478.

The product of its digits is 600, while the sum is 23.

The square root of 56121521 is about 7491.4298368202. The cubic root of 56121521 is about 382.8627762739.

Adding to 56121521 its reverse (12512165), we get a palindrome (68633686).

The spelling of 56121521 in words is "fifty-six million, one hundred twenty-one thousand, five hundred twenty-one".