21872870 has 8 divisors (see below), whose sum is σ = 39371184. Its totient is φ = 8749144.

The previous prime is 21872867. The next prime is 21872881. The reversal of 21872870 is 7827812.

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 21872870.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1093634 + ... + 1093653.

It is an arithmetic number, because the mean of its divisors is an integer number (4921398).

Almost surely, 2^21872870 is an apocalyptic number.

21872870 is a deficient number, since it is larger than the sum of its proper divisors (17498314).

21872870 is a wasteful number, since it uses less digits than its factorization.

21872870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2187294.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 21872870 is about 4676.8440213460. The cubic root of 21872870 is about 279.6631578640.

The spelling of 21872870 in words is "twenty-one million, eight hundred seventy-two thousand, eight hundred seventy".