20567221 has 4 divisors (see below), whose sum is σ = 21461472. Its totient is φ = 19672972.

The previous prime is 20567213. The next prime is 20567231. The reversal of 20567221 is 12276502.

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 20567221 - 2³ = 20567213 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 (20567231) 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, 447091 + ... + 447136.

It is an arithmetic number, because the mean of its divisors is an integer number (5365368).

Almost surely, 2^20567221 is an apocalyptic number.

It is an amenable number.

20567221 is a deficient number, since it is larger than the sum of its proper divisors (894251).

20567221 is an equidigital number, since it uses as much as digits as its factorization.

20567221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894250.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20567221 is about 4535.1098112394. The cubic root of 20567221 is about 273.9840019430.

The spelling of 20567221 in words is "twenty million, five hundred sixty-seven thousand, two hundred twenty-one".