21332180 has 24 divisors (see below), whose sum is σ = 45007872. Its totient is φ = 8492832.

The previous prime is 21332159. The next prime is 21332183. The reversal of 21332180 is 8123312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21332183) 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, 2069 + ... + 6851.

It is an arithmetic number, because the mean of its divisors is an integer number (1875328).

Almost surely, 2^21332180 is an apocalyptic number.

21332180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21332180 is an abundant number, since it is smaller than the sum of its proper divisors (23675692).

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

21332180 is a wasteful number, since it uses less digits than its factorization.

21332180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5015 (or 5013 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21332180 is about 4618.6772998338. The cubic root of 21332180 is about 277.3395116710.

Adding to 21332180 its reverse (8123312), we get a palindrome (29455492).

It can be divided in two parts, 21332 and 180, that added together give a palindrome (21512).

The spelling of 21332180 in words is "twenty-one million, three hundred thirty-two thousand, one hundred eighty".