20584021 has 2 divisors, whose sum is σ = 20584022. Its totient is φ = 20584020.

The previous prime is 20584013. The next prime is 20584027. The reversal of 20584021 is 12048502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18922500 + 1661521 = 4350^2 + 1289^2 .

It is a cyclic number.

It is not a de Polignac number, because 20584021 - 2³ = 20584013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20583983 and 20584001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20584027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10292010 + 10292011.

It is an arithmetic number, because the mean of its divisors is an integer number (10292011).

Almost surely, 2^20584021 is an apocalyptic number.

It is an amenable number.

20584021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20584021 is an equidigital number, since it uses as much as digits as its factorization.

20584021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 20584021 is about 4536.9616485044. The cubic root of 20584021 is about 274.0585814325.

The spelling of 20584021 in words is "twenty million, five hundred eighty-four thousand, twenty-one".