20822021 has 4 divisors (see below), whose sum is σ = 22714944. Its totient is φ = 18929100.

The previous prime is 20822017. The next prime is 20822033. The reversal of 20822021 is 12022802.

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 20822021 - 2² = 20822017 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 (20822051) 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, 946445 + ... + 946466.

It is an arithmetic number, because the mean of its divisors is an integer number (5678736).

Almost surely, 2^20822021 is an apocalyptic number.

It is an amenable number.

20822021 is a deficient number, since it is larger than the sum of its proper divisors (1892923).

20822021 is a wasteful number, since it uses less digits than its factorization.

20822021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1892922.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 20822021 is about 4563.1152735823. The cubic root of 20822021 is about 275.1107917220.

Adding to 20822021 its reverse (12022802), we get a palindrome (32844823).

The spelling of 20822021 in words is "twenty million, eight hundred twenty-two thousand, twenty-one".