20056521 has 4 divisors (see below), whose sum is σ = 26742032. Its totient is φ = 13371012.

The previous prime is 20056511. The next prime is 20056523. The reversal of 20056521 is 12565002.

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 not a de Polignac number, because 20056521 - 2¹⁵ = 20023753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20056523) 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, 3342751 + ... + 3342756.

It is an arithmetic number, because the mean of its divisors is an integer number (6685508).

Almost surely, 2^20056521 is an apocalyptic number.

It is an amenable number.

20056521 is a deficient number, since it is larger than the sum of its proper divisors (6685511).

20056521 is an equidigital number, since it uses as much as digits as its factorization.

20056521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6685510.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20056521 is about 4478.4507365829. The cubic root of 20056521 is about 271.6972238243.

The spelling of 20056521 in words is "twenty million, fifty-six thousand, five hundred twenty-one".