20639120651 has 2 divisors, whose sum is σ = 20639120652. Its totient is φ = 20639120650.

The previous prime is 20639120617. The next prime is 20639120681. The reversal of 20639120651 is 15602193602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20639120651 is a prime.

It is not a weakly prime, because it can be changed into another prime (20639120611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10319560325 + 10319560326.

It is an arithmetic number, because the mean of its divisors is an integer number (10319560326).

Almost surely, 2^20639120651 is an apocalyptic number.

20639120651 is a deficient number, since it is larger than the sum of its proper divisors (1).

20639120651 is an equidigital number, since it uses as much as digits as its factorization.

20639120651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

The spelling of 20639120651 in words is "twenty billion, six hundred thirty-nine million, one hundred twenty thousand, six hundred fifty-one".