20648030021 has 2 divisors, whose sum is σ = 20648030022. Its totient is φ = 20648030020.

The previous prime is 20648029937. The next prime is 20648030027. The reversal of 20648030021 is 12003084602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16138907521 + 4509122500 = 127039^2 + 67150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20648030021 is a prime.

It is a super-2 number, since 2×20648030021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20648030027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10324015010 + 10324015011.

It is an arithmetic number, because the mean of its divisors is an integer number (10324015011).

Almost surely, 2^20648030021 is an apocalyptic number.

It is an amenable number.

20648030021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20648030021 is an equidigital number, since it uses as much as digits as its factorization.

20648030021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 26.

The spelling of 20648030021 in words is "twenty billion, six hundred forty-eight million, thirty thousand, twenty-one".