222645906 has 144 divisors (see below), whose sum is σ = 614615040. Its totient is φ = 57818880.

The previous prime is 222645893. The next prime is 222645919. The reversal of 222645906 is 609546222.

222645906 is a `hidden beast` number, since 2 + 2 + 2 + 64 + 590 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (222645893) and next prime (222645919).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 464575 + ... + 465053.

It is an arithmetic number, because the mean of its divisors is an integer number (4268160).

Almost surely, 2^222645906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 222645906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307307520).

222645906 is an abundant number, since it is smaller than the sum of its proper divisors (391969134).

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

222645906 is a wasteful number, since it uses less digits than its factorization.

222645906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549 (or 539 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 222645906 is about 14921.3238688797. The cubic root of 222645906 is about 606.0915621542.

The spelling of 222645906 in words is "two hundred twenty-two million, six hundred forty-five thousand, nine hundred six".