21930066 has 24 divisors (see below), whose sum is σ = 50016720. Its totient is φ = 6925176.

The previous prime is 21929993. The next prime is 21930101. The reversal of 21930066 is 66003912.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31720 + ... + 32403.

It is an arithmetic number, because the mean of its divisors is an integer number (2084030).

Almost surely, 2^21930066 is an apocalyptic number.

21930066 is an abundant number, since it is smaller than the sum of its proper divisors (28086654).

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

21930066 is a wasteful number, since it uses less digits than its factorization.

21930066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64150 (or 64147 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 21930066 is about 4682.9548364254. The cubic root of 21930066 is about 279.9067121199.

Adding to 21930066 its reverse (66003912), we get a palindrome (87933978).

The spelling of 21930066 in words is "twenty-one million, nine hundred thirty thousand, sixty-six".