21613897133 has 4 divisors (see below), whose sum is σ = 21625414140. Its totient is φ = 21602380128.

The previous prime is 21613897091. The next prime is 21613897139. The reversal of 21613897133 is 33179831612.

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 8269719844 + 13344177289 = 90938^2 + 115517^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21613897133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613897139) 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, 5755688 + ... + 5759441.

It is an arithmetic number, because the mean of its divisors is an integer number (5406353535).

Almost surely, 2^21613897133 is an apocalyptic number.

It is an amenable number.

21613897133 is a deficient number, since it is larger than the sum of its proper divisors (11517007).

21613897133 is a wasteful number, since it uses less digits than its factorization.

21613897133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11517006.

The product of its digits is 163296, while the sum is 44.

The spelling of 21613897133 in words is "twenty-one billion, six hundred thirteen million, eight hundred ninety-seven thousand, one hundred thirty-three".