222158921 has 4 divisors (see below), whose sum is σ = 222293700. Its totient is φ = 222024144.

The previous prime is 222158903. The next prime is 222158933. The reversal of 222158921 is 129851222.

It is a happy number.

222158921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129851222 = 2 ⋅64925611.

It can be written as a sum of positive squares in 2 ways, for example, as 138180025 + 83978896 = 11755^2 + 9164^2 .

It is a cyclic number.

It is not a de Polignac number, because 222158921 - 2²⁶ = 155050057 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (222158971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64886 + ... + 68223.

It is an arithmetic number, because the mean of its divisors is an integer number (55573425).

Almost surely, 2^222158921 is an apocalyptic number.

It is an amenable number.

222158921 is a deficient number, since it is larger than the sum of its proper divisors (134779).

222158921 is a wasteful number, since it uses less digits than its factorization.

222158921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134778.

The product of its digits is 5760, while the sum is 32.

The square root of 222158921 is about 14904.9965112374. The cubic root of 222158921 is about 605.6493458383.

The spelling of 222158921 in words is "two hundred twenty-two million, one hundred fifty-eight thousand, nine hundred twenty-one".