20767921651 has 2 divisors, whose sum is σ = 20767921652. Its totient is φ = 20767921650.

The previous prime is 20767921639. The next prime is 20767921777. The reversal of 20767921651 is 15612976702.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20767921651 is a prime.

It is not a weakly prime, because it can be changed into another prime (20767121651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10383960825 + 10383960826.

It is an arithmetic number, because the mean of its divisors is an integer number (10383960826).

Almost surely, 2^20767921651 is an apocalyptic number.

20767921651 is a deficient number, since it is larger than the sum of its proper divisors (1).

20767921651 is an equidigital number, since it uses as much as digits as its factorization.

20767921651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 317520, while the sum is 46.

The spelling of 20767921651 in words is "twenty billion, seven hundred sixty-seven million, nine hundred twenty-one thousand, six hundred fifty-one".