20768913391 has 2 divisors, whose sum is σ = 20768913392. Its totient is φ = 20768913390.

The previous prime is 20768913343. The next prime is 20768913421. The reversal of 20768913391 is 19331986702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20768913391 - 2¹⁵ = 20768880623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20768910391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10384456695 + 10384456696.

It is an arithmetic number, because the mean of its divisors is an integer number (10384456696).

Almost surely, 2^20768913391 is an apocalyptic number.

20768913391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20768913391 is an equidigital number, since it uses as much as digits as its factorization.

20768913391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 49.

The spelling of 20768913391 in words is "twenty billion, seven hundred sixty-eight million, nine hundred thirteen thousand, three hundred ninety-one".