21859664169 has 32 divisors (see below), whose sum is σ = 34330024960. Its totient is φ = 12112898112.

The previous prime is 21859664153. The next prime is 21859664173. The reversal of 21859664169 is 96146695812.

It is not a de Polignac number, because 21859664169 - 2⁴ = 21859664153 is a prime.

It is a super-2 number, since 2×21859664169² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21859164169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38439 + ... + 212595.

It is an arithmetic number, because the mean of its divisors is an integer number (1072813280).

Almost surely, 2^21859664169 is an apocalyptic number.

It is an amenable number.

21859664169 is a deficient number, since it is larger than the sum of its proper divisors (12470360791).

21859664169 is a wasteful number, since it uses less digits than its factorization.

21859664169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174349.

The product of its digits is 5598720, while the sum is 57.

The spelling of 21859664169 in words is "twenty-one billion, eight hundred fifty-nine million, six hundred sixty-four thousand, one hundred sixty-nine".