20056021 has 2 divisors, whose sum is σ = 20056022. Its totient is φ = 20056020.

The previous prime is 20056013. The next prime is 20056027. The reversal of 20056021 is 12065002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19236996 + 819025 = 4386^2 + 905^2 .

It is a cyclic number.

It is not a de Polignac number, because 20056021 - 2³ = 20056013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20055986 and 20056004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20056027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10028010 + 10028011.

It is an arithmetic number, because the mean of its divisors is an integer number (10028011).

Almost surely, 2^20056021 is an apocalyptic number.

It is an amenable number.

20056021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20056021 is an equidigital number, since it uses as much as digits as its factorization.

20056021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20056021 is about 4478.3949133590. The cubic root of 20056021 is about 271.6949660426.

The spelling of 20056021 in words is "twenty million, fifty-six thousand, twenty-one".