21852180 has 240 divisors, whose sum is σ = 81962496. Its totient is φ = 4769280.

The previous prime is 21852169. The next prime is 21852197. The reversal of 21852180 is 8125812.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 464917 + ... + 464963.

Almost surely, 2^21852180 is an apocalyptic number.

21852180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21852180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40981248).

21852180 is an abundant number, since it is smaller than the sum of its proper divisors (60110316).

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

21852180 is a wasteful number, since it uses less digits than its factorization.

21852180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 21852180 is about 4674.6315362818. The cubic root of 21852180 is about 279.5749503245.

Adding to 21852180 its reverse (8125812), we get a palindrome (29977992).

The spelling of 21852180 in words is "twenty-one million, eight hundred fifty-two thousand, one hundred eighty".