21326172 has 36 divisors (see below), whose sum is σ = 57886920. Its totient is φ = 6093024.

The previous prime is 21326161. The next prime is 21326213. The reversal of 21326172 is 27162312.

It is a super-2 number, since 2×21326172² = 909611224347168, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17547 + ... + 18722.

It is an arithmetic number, because the mean of its divisors is an integer number (1607970).

Almost surely, 2^21326172 is an apocalyptic number.

It is an amenable number.

21326172 is an abundant number, since it is smaller than the sum of its proper divisors (36560748).

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

21326172 is a wasteful number, since it uses less digits than its factorization.

21326172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36290 (or 36281 counting only the distinct ones).

The product of its digits is 1008, while the sum is 24.

The square root of 21326172 is about 4618.0268513728. The cubic root of 21326172 is about 277.3134725720.

Adding to 21326172 its reverse (27162312), we get a palindrome (48488484).

The spelling of 21326172 in words is "twenty-one million, three hundred twenty-six thousand, one hundred seventy-two".