222021645 has 32 divisors (see below), whose sum is σ = 380719872. Its totient is φ = 110195712.

The previous prime is 222021641. The next prime is 222021733. The reversal of 222021645 is 546120222.

It is a happy number.

222021645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 222021645 - 2² = 222021641 is a prime.

It is a super-3 number, since 3×222021645³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222021641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4069 + ... + 21461.

It is an arithmetic number, because the mean of its divisors is an integer number (11897496).

Almost surely, 2^222021645 is an apocalyptic number.

It is an amenable number.

222021645 is a deficient number, since it is larger than the sum of its proper divisors (158698227).

222021645 is a wasteful number, since it uses less digits than its factorization.

222021645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17461.

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 222021645 is about 14900.3907666880. The cubic root of 222021645 is about 605.5245729207.

Adding to 222021645 its reverse (546120222), we get a palindrome (768141867).

The spelling of 222021645 in words is "two hundred twenty-two million, twenty-one thousand, six hundred forty-five".