20919462917 has 2 divisors, whose sum is σ = 20919462918. Its totient is φ = 20919462916.

The previous prime is 20919462901. The next prime is 20919462919. The reversal of 20919462917 is 71926491902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15945123076 + 4974339841 = 126274^2 + 70529^2 .

It is a cyclic number.

It is not a de Polignac number, because 20919462917 - 2⁴ = 20919462901 is a prime.

Together with 20919462919, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20919462919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10459731458 + 10459731459.

It is an arithmetic number, because the mean of its divisors is an integer number (10459731459).

Almost surely, 2^20919462917 is an apocalyptic number.

It is an amenable number.

20919462917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20919462917 is an equidigital number, since it uses as much as digits as its factorization.

20919462917 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 50.

The spelling of 20919462917 in words is "twenty billion, nine hundred nineteen million, four hundred sixty-two thousand, nine hundred seventeen".