21888942 has 16 divisors (see below), whose sum is σ = 44204160. Its totient is φ = 7225272.

The previous prime is 21888917. The next prime is 21888943. The reversal of 21888942 is 24988812.

It is a junction number, because it is equal to n+sod(n) for n = 21888894 and 21888903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21888943) 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, 17092 + ... + 18327.

It is an arithmetic number, because the mean of its divisors is an integer number (2762760).

Almost surely, 2^21888942 is an apocalyptic number.

21888942 is an abundant number, since it is smaller than the sum of its proper divisors (22315218).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21888942 is a wasteful number, since it uses less digits than its factorization.

21888942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35527.

The product of its digits is 73728, while the sum is 42.

The square root of 21888942 is about 4678.5619585509. The cubic root of 21888942 is about 279.7316391351.

The spelling of 21888942 in words is "twenty-one million, eight hundred eighty-eight thousand, nine hundred forty-two".