21706552159 has 2 divisors, whose sum is σ = 21706552160. Its totient is φ = 21706552158.

The previous prime is 21706552099. The next prime is 21706552163. The reversal of 21706552159 is 95125560712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21706552159 - 2²³ = 21698163551 is a prime.

It is a super-2 number, since 2×21706552159² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21706552169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10853276079 + 10853276080.

It is an arithmetic number, because the mean of its divisors is an integer number (10853276080).

Almost surely, 2^21706552159 is an apocalyptic number.

21706552159 is a deficient number, since it is larger than the sum of its proper divisors (1).

21706552159 is an equidigital number, since it uses as much as digits as its factorization.

21706552159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 189000, while the sum is 43.

The spelling of 21706552159 in words is "twenty-one billion, seven hundred six million, five hundred fifty-two thousand, one hundred fifty-nine".