221981123 has 24 divisors (see below), whose sum is σ = 292738320. Its totient is φ = 166380480.

The previous prime is 221981107. The next prime is 221981143. The reversal of 221981123 is 321189122.

It is not a de Polignac number, because 221981123 - 2⁴ = 221981107 is a prime.

It is a super-2 number, since 2×221981123² = 98551237936682258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221981143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2933 + ... + 21273.

It is an arithmetic number, because the mean of its divisors is an integer number (12197430).

Almost surely, 2^221981123 is an apocalyptic number.

221981123 is a deficient number, since it is larger than the sum of its proper divisors (70757197).

221981123 is a wasteful number, since it uses less digits than its factorization.

221981123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18387 (or 18380 counting only the distinct ones).

The product of its digits is 1728, while the sum is 29.

The square root of 221981123 is about 14899.0309416418. The cubic root of 221981123 is about 605.4877318285.

The spelling of 221981123 in words is "two hundred twenty-one million, nine hundred eighty-one thousand, one hundred twenty-three".