21966199 has 8 divisors (see below), whose sum is σ = 22321152. Its totient is φ = 21613560.

The previous prime is 21966181. The next prime is 21966209. The reversal of 21966199 is 99166912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21966199 - 2⁵ = 21966167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21966149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31444 + ... + 32134.

It is an arithmetic number, because the mean of its divisors is an integer number (2790144).

Almost surely, 2^21966199 is an apocalyptic number.

21966199 is a deficient number, since it is larger than the sum of its proper divisors (354953).

21966199 is an equidigital number, since it uses as much as digits as its factorization.

21966199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157.

The product of its digits is 52488, while the sum is 43.

The square root of 21966199 is about 4686.8111760556. The cubic root of 21966199 is about 280.0603568865.

The spelling of 21966199 in words is "twenty-one million, nine hundred sixty-six thousand, one hundred ninety-nine".