21966330 has 16 divisors (see below), whose sum is σ = 52719264. Its totient is φ = 5857680.

The previous prime is 21966317. The next prime is 21966331. The reversal of 21966330 is 3366912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 732211 = 21966330 / (2 + 1 + 9 + 6 + 6 + 3 + 3 + 0).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21966331) 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, 366076 + ... + 366135.

It is an arithmetic number, because the mean of its divisors is an integer number (3294954).

Almost surely, 2^21966330 is an apocalyptic number.

21966330 is an abundant number, since it is smaller than the sum of its proper divisors (30752934).

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

21966330 is a wasteful number, since it uses less digits than its factorization.

21966330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732221.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 21966330 is about 4686.8251514218. The cubic root of 21966330 is about 280.0609136181.

The spelling of 21966330 in words is "twenty-one million, nine hundred sixty-six thousand, three hundred thirty".