21966089 has 4 divisors (see below), whose sum is σ = 22179456. Its totient is φ = 21752724.

The previous prime is 21966067. The next prime is 21966097. The reversal of 21966089 is 98066912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21966089 - 2⁸ = 21965833 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21966019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106529 + ... + 106734.

It is an arithmetic number, because the mean of its divisors is an integer number (5544864).

Almost surely, 2^21966089 is an apocalyptic number.

It is an amenable number.

21966089 is a deficient number, since it is larger than the sum of its proper divisors (213367).

21966089 is a wasteful number, since it uses less digits than its factorization.

21966089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213366.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 21966089 is about 4686.7994409832. The cubic root of 21966089 is about 280.0598894002.

The spelling of 21966089 in words is "twenty-one million, nine hundred sixty-six thousand, eighty-nine".