21885066 has 72 divisors (see below), whose sum is σ = 57264480. Its totient is φ = 6246072.

The previous prime is 21885041. The next prime is 21885067. The reversal of 21885066 is 66058812.

It is a happy number.

It is a super-2 number, since 2×21885066² = 957912227648712, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21885066.

It is not an unprimeable number, because it can be changed into a prime (21885067) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 23355 + ... + 24273.

It is an arithmetic number, because the mean of its divisors is an integer number (795340).

Almost surely, 2^21885066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21885066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28632240).

21885066 is an abundant number, since it is smaller than the sum of its proper divisors (35379414).

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

21885066 is an equidigital number, since it uses as much as digits as its factorization.

21885066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950 (or 931 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 21885066 is about 4678.1477103657. The cubic root of 21885066 is about 279.7151269340.

The spelling of 21885066 in words is "twenty-one million, eight hundred eighty-five thousand, sixty-six".