20501207621 has 2 divisors, whose sum is σ = 20501207622. Its totient is φ = 20501207620.

The previous prime is 20501207609. The next prime is 20501207633. The reversal of 20501207621 is 12670210502.

It is a balanced prime because it is at equal distance from previous prime (20501207609) and next prime (20501207633).

It can be written as a sum of positive squares in only one way, i.e., 20309385121 + 191822500 = 142511^2 + 13850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20501207621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20501207521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10250603810 + 10250603811.

It is an arithmetic number, because the mean of its divisors is an integer number (10250603811).

Almost surely, 2^20501207621 is an apocalyptic number.

It is an amenable number.

20501207621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20501207621 is an equidigital number, since it uses as much as digits as its factorization.

20501207621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 26.

The spelling of 20501207621 in words is "twenty billion, five hundred one million, two hundred seven thousand, six hundred twenty-one".