21944610817 has 8 divisors (see below), whose sum is σ = 22109433192. Its totient is φ = 21779856000.

The previous prime is 21944610791. The next prime is 21944610881. The reversal of 21944610817 is 71801644912.

It can be written as a sum of positive squares in 4 ways, for example, as 8525936896 + 13418673921 = 92336^2 + 115839^2 .

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 21944610817 - 2⁷ = 21944610689 is a prime.

It is a super-3 number, since 3×21944610817³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21944610217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 772567 + ... + 800467.

It is an arithmetic number, because the mean of its divisors is an integer number (2763679149).

Almost surely, 2^21944610817 is an apocalyptic number.

It is an amenable number.

21944610817 is a deficient number, since it is larger than the sum of its proper divisors (164822375).

21944610817 is a wasteful number, since it uses less digits than its factorization.

21944610817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33779.

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 21944610817 in words is "twenty-one billion, nine hundred forty-four million, six hundred ten thousand, eight hundred seventeen".