21985182 has 56 divisors (see below), whose sum is σ = 52411536. Its totient is φ = 6889536.

The previous prime is 21985153. The next prime is 21985189. The reversal of 21985182 is 28158912.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21985189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 24343 + ... + 25229.

Almost surely, 2^21985182 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21985182, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26205768).

21985182 is an abundant number, since it is smaller than the sum of its proper divisors (30426354).

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

21985182 is an equidigital number, since it uses as much as digits as its factorization.

21985182 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 924 (or 909 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 21985182 is about 4688.8358896425. The cubic root of 21985182 is about 280.1410089075.

The spelling of 21985182 in words is "twenty-one million, nine hundred eighty-five thousand, one hundred eighty-two".