20605733021 has 2 divisors, whose sum is σ = 20605733022. Its totient is φ = 20605733020.

The previous prime is 20605733017. The next prime is 20605733023. The reversal of 20605733021 is 12033750602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18386004025 + 2219728996 = 135595^2 + 47114^2 .

It is a cyclic number.

It is not a de Polignac number, because 20605733021 - 2² = 20605733017 is a prime.

Together with 20605733023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20605733023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10302866510 + 10302866511.

It is an arithmetic number, because the mean of its divisors is an integer number (10302866511).

Almost surely, 2^20605733021 is an apocalyptic number.

It is an amenable number.

20605733021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20605733021 is an equidigital number, since it uses as much as digits as its factorization.

20605733021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 29.

The spelling of 20605733021 in words is "twenty billion, six hundred five million, seven hundred thirty-three thousand, twenty-one".