21666092 has 48 divisors (see below), whose sum is σ = 47900160. Its totient is φ = 8355072.

The previous prime is 21666091. The next prime is 21666101. The reversal of 21666092 is 29066612.

It is not an unprimeable number, because it can be changed into a prime (21666091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9959 + ... + 11937.

It is an arithmetic number, because the mean of its divisors is an integer number (997920).

Almost surely, 2^21666092 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21666092, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23950080).

21666092 is an abundant number, since it is smaller than the sum of its proper divisors (26234068).

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

21666092 is a wasteful number, since it uses less digits than its factorization.

21666092 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2030 (or 2028 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21666092 is about 4654.6849517449. The cubic root of 21666092 is about 278.7790888423.

The spelling of 21666092 in words is "twenty-one million, six hundred sixty-six thousand, ninety-two".