21667613017 has 4 divisors (see below), whose sum is σ = 21669577380. Its totient is φ = 21665648656.

The previous prime is 21667612919. The next prime is 21667613039. The reversal of 21667613017 is 71031676612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15429614656 + 6237998361 = 124216^2 + 78981^2 .

It is a cyclic number.

It is not a de Polignac number, because 21667613017 - 2¹¹ = 21667610969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21667613087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 965542 + ... + 987727.

It is an arithmetic number, because the mean of its divisors is an integer number (5417394345).

Almost surely, 2^21667613017 is an apocalyptic number.

It is an amenable number.

21667613017 is a deficient number, since it is larger than the sum of its proper divisors (1964363).

21667613017 is a wasteful number, since it uses less digits than its factorization.

21667613017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1964362.

The product of its (nonzero) digits is 63504, while the sum is 40.

The spelling of 21667613017 in words is "twenty-one billion, six hundred sixty-seven million, six hundred thirteen thousand, seventeen".