221522123 has 4 divisors (see below), whose sum is σ = 221692920. Its totient is φ = 221351328.

The previous prime is 221522113. The next prime is 221522137. The reversal of 221522123 is 321225122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 321225122 = 2 ⋅160612561.

It is a cyclic number.

It is not a de Polignac number, because 221522123 - 2¹⁸ = 221259979 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221522095 and 221522104.

It is not an unprimeable number, because it can be changed into a prime (221522113) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 83438 + ... + 86051.

It is an arithmetic number, because the mean of its divisors is an integer number (55423230).

Almost surely, 2^221522123 is an apocalyptic number.

221522123 is a deficient number, since it is larger than the sum of its proper divisors (170797).

221522123 is a wasteful number, since it uses less digits than its factorization.

221522123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170796.

The product of its digits is 480, while the sum is 20.

The square root of 221522123 is about 14883.6192843004. The cubic root of 221522123 is about 605.0701127678.

Adding to 221522123 its reverse (321225122), we get a palindrome (542747245).

The spelling of 221522123 in words is "two hundred twenty-one million, five hundred twenty-two thousand, one hundred twenty-three".