21955266 has 16 divisors (see below), whose sum is σ = 48789600. Its totient is φ = 7318404.

The previous prime is 21955247. The next prime is 21955267. The reversal of 21955266 is 66255912.

It is a super-3 number, since 3×21955266³ (a number of 23 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21955266.

It is not an unprimeable number, because it can be changed into a prime (21955267) 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, 203236 + ... + 203343.

It is an arithmetic number, because the mean of its divisors is an integer number (3049350).

Almost surely, 2^21955266 is an apocalyptic number.

21955266 is an abundant number, since it is smaller than the sum of its proper divisors (26834334).

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

21955266 is a wasteful number, since it uses less digits than its factorization.

21955266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406590 (or 406584 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 21955266 is about 4685.6446728278. The cubic root of 21955266 is about 280.0138853658.

The spelling of 21955266 in words is "twenty-one million, nine hundred fifty-five thousand, two hundred sixty-six".