21876413 has 4 divisors (see below), whose sum is σ = 23559228. Its totient is φ = 20193600.

The previous prime is 21876403. The next prime is 21876419. The reversal of 21876413 is 31467812.

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 13935289 + 7941124 = 3733^2 + 2818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21876413 - 2⁴ = 21876397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21876413.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21876419) 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, 841388 + ... + 841413.

It is an arithmetic number, because the mean of its divisors is an integer number (5889807).

Almost surely, 2^21876413 is an apocalyptic number.

It is an amenable number.

21876413 is a deficient number, since it is larger than the sum of its proper divisors (1682815).

21876413 is a wasteful number, since it uses less digits than its factorization.

21876413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1682814.

The product of its digits is 8064, while the sum is 32.

The square root of 21876413 is about 4677.2227870821. Note that the first 3 decimals coincide. The cubic root of 21876413 is about 279.6782571335.

The spelling of 21876413 in words is "twenty-one million, eight hundred seventy-six thousand, four hundred thirteen".