20738021 has 2 divisors, whose sum is σ = 20738022. Its totient is φ = 20738020.

The previous prime is 20737967. The next prime is 20738033. The reversal of 20738021 is 12083702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17181025 + 3556996 = 4145^2 + 1886^2 .

It is a cyclic number.

It is not a de Polignac number, because 20738021 - 2¹⁴ = 20721637 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20738051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10369010 + 10369011.

It is an arithmetic number, because the mean of its divisors is an integer number (10369011).

Almost surely, 2^20738021 is an apocalyptic number.

It is an amenable number.

20738021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20738021 is an equidigital number, since it uses as much as digits as its factorization.

20738021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20738021 is about 4553.9017336785. The cubic root of 20738021 is about 274.7403433375.

The spelling of 20738021 in words is "twenty million, seven hundred thirty-eight thousand, twenty-one".