21642160 has 20 divisors (see below), whose sum is σ = 50318208. Its totient is φ = 8656832.

The previous prime is 21642143. The next prime is 21642169. The reversal of 21642160 is 6124612.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21642169) 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, 135184 + ... + 135343.

Almost surely, 2^21642160 is an apocalyptic number.

21642160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21642160 is an abundant number, since it is smaller than the sum of its proper divisors (28676048).

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

21642160 is a wasteful number, since it uses less digits than its factorization.

21642160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270540 (or 270534 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21642160 is about 4652.1134981855. The cubic root of 21642160 is about 278.6764061318.

Adding to 21642160 its reverse (6124612), we get a palindrome (27766772).

The spelling of 21642160 in words is "twenty-one million, six hundred forty-two thousand, one hundred sixty".