21881914 has 8 divisors (see below), whose sum is σ = 33062868. Its totient is φ = 10860960.

The previous prime is 21881903. The next prime is 21881917. The reversal of 21881914 is 41918812.

It can be written as a sum of positive squares in 2 ways, for example, as 19580625 + 2301289 = 4425^2 + 1517^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21881914.

It is not an unprimeable number, because it can be changed into a prime (21881917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39657 + ... + 40204.

Almost surely, 2^21881914 is an apocalyptic number.

21881914 is a deficient number, since it is larger than the sum of its proper divisors (11180954).

21881914 is a wasteful number, since it uses less digits than its factorization.

21881914 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80000.

The product of its digits is 4608, while the sum is 34.

The square root of 21881914 is about 4677.8108127627. The cubic root of 21881914 is about 279.7016976179.

The spelling of 21881914 in words is "twenty-one million, eight hundred eighty-one thousand, nine hundred fourteen".