21915066 has 16 divisors (see below), whose sum is σ = 44763264. Its totient is φ = 7149504.

The previous prime is 21915059. The next prime is 21915077. The reversal of 21915066 is 66051912.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38575 + ... + 39138.

It is an arithmetic number, because the mean of its divisors is an integer number (2797704).

Almost surely, 2^21915066 is an apocalyptic number.

21915066 is an abundant number, since it is smaller than the sum of its proper divisors (22848198).

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

21915066 is a wasteful number, since it uses less digits than its factorization.

21915066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77765.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 21915066 is about 4681.3530095476. The cubic root of 21915066 is about 279.8428795363.

Adding to 21915066 its reverse (66051912), we get a palindrome (87966978).

The spelling of 21915066 in words is "twenty-one million, nine hundred fifteen thousand, sixty-six".