21488172 has 24 divisors (see below), whose sum is σ = 50265600. Its totient is φ = 7144656.

The previous prime is 21488171. The next prime is 21488179. The reversal of 21488172 is 27188412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21488171) 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, 3229 + ... + 7307.

It is an arithmetic number, because the mean of its divisors is an integer number (2094400).

Almost surely, 2^21488172 is an apocalyptic number.

It is an amenable number.

21488172 is an abundant number, since it is smaller than the sum of its proper divisors (28777428).

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

21488172 is a wasteful number, since it uses less digits than its factorization.

21488172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4525 (or 4523 counting only the distinct ones).

The product of its digits is 7168, while the sum is 33.

The square root of 21488172 is about 4635.5336262398. The cubic root of 21488172 is about 278.0138874763.

The spelling of 21488172 in words is "twenty-one million, four hundred eighty-eight thousand, one hundred seventy-two".