20928551291 has 2 divisors, whose sum is σ = 20928551292. Its totient is φ = 20928551290.

The previous prime is 20928551261. The next prime is 20928551323. The reversal of 20928551291 is 19215582902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20928551291 - 2²² = 20924356987 is a prime.

It is not a weakly prime, because it can be changed into another prime (20928551221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10464275645 + 10464275646.

It is an arithmetic number, because the mean of its divisors is an integer number (10464275646).

Almost surely, 2^20928551291 is an apocalyptic number.

20928551291 is a deficient number, since it is larger than the sum of its proper divisors (1).

20928551291 is an equidigital number, since it uses as much as digits as its factorization.

20928551291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129600, while the sum is 44.

The spelling of 20928551291 in words is "twenty billion, nine hundred twenty-eight million, five hundred fifty-one thousand, two hundred ninety-one".