21860144 has 20 divisors (see below), whose sum is σ = 42507696. Its totient is φ = 10890432.

The previous prime is 21860117. The next prime is 21860183. The reversal of 21860144 is 44106812.

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, 2357 + ... + 7019.

Almost surely, 2^21860144 is an apocalyptic number.

It is an amenable number.

21860144 is a deficient number, since it is larger than the sum of its proper divisors (20647552).

21860144 is a wasteful number, since it uses less digits than its factorization.

21860144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4964 (or 4958 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21860144 is about 4675.4832905273. The cubic root of 21860144 is about 279.6089097811.

Adding to 21860144 its reverse (44106812), we get a palindrome (65966956).

The spelling of 21860144 in words is "twenty-one million, eight hundred sixty thousand, one hundred forty-four".