21885613 has 8 divisors (see below), whose sum is σ = 23344632. Its totient is φ = 20445696.

The previous prime is 21885593. The next prime is 21885623. The reversal of 21885613 is 31658812.

It can be written as a sum of positive squares in 4 ways, for example, as 1119364 + 20766249 = 1058^2 + 4557^2 .

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

It is not a de Polignac number, because 21885613 - 2¹³ = 21877421 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 (21885623) 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, 2370 + ... + 7027.

It is an arithmetic number, because the mean of its divisors is an integer number (2918079).

Almost surely, 2^21885613 is an apocalyptic number.

It is an amenable number.

21885613 is a deficient number, since it is larger than the sum of its proper divisors (1459019).

21885613 is a wasteful number, since it uses less digits than its factorization.

21885613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9551.

The product of its digits is 11520, while the sum is 34.

The square root of 21885613 is about 4678.2061733104. The cubic root of 21885613 is about 279.7174573344.

The spelling of 21885613 in words is "twenty-one million, eight hundred eighty-five thousand, six hundred thirteen".