21615844969 has 8 divisors (see below), whose sum is σ = 22838112000. Its totient is φ = 20402037072.

The previous prime is 21615844949. The next prime is 21615845029. The reversal of 21615844969 is 96944851612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21615844969 - 2⁷ = 21615844841 is a prime.

It is a super-2 number, since 2×21615844969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21615844949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2109529 + ... + 2119750.

It is an arithmetic number, because the mean of its divisors is an integer number (2854764000).

Almost surely, 2^21615844969 is an apocalyptic number.

It is an amenable number.

21615844969 is a deficient number, since it is larger than the sum of its proper divisors (1222267031).

21615844969 is a wasteful number, since it uses less digits than its factorization.

21615844969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4229567.

The product of its digits is 3732480, while the sum is 55.

The spelling of 21615844969 in words is "twenty-one billion, six hundred fifteen million, eight hundred forty-four thousand, nine hundred sixty-nine".