20260021 has 2 divisors, whose sum is σ = 20260022. Its totient is φ = 20260020.

The previous prime is 20260013. The next prime is 20260091. The reversal of 20260021 is 12006202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20151121 + 108900 = 4489^2 + 330^2 .

It is a cyclic number.

It is not a de Polignac number, because 20260021 - 2³ = 20260013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20259983 and 20260010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20260001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10130010 + 10130011.

It is an arithmetic number, because the mean of its divisors is an integer number (10130011).

Almost surely, 2^20260021 is an apocalyptic number.

It is an amenable number.

20260021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20260021 is an equidigital number, since it uses as much as digits as its factorization.

20260021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20260021 is about 4501.1133067276. The cubic root of 20260021 is about 272.6130429065.

Adding to 20260021 its reverse (12006202), we get a palindrome (32266223).

The spelling of 20260021 in words is "twenty million, two hundred sixty thousand, twenty-one".