221944281 has 16 divisors (see below), whose sum is σ = 320093760. Its totient is φ = 135979200.

The previous prime is 221944249. The next prime is 221944313. The reversal of 221944281 is 182449122.

It is an interprime number because it is at equal distance from previous prime (221944249) and next prime (221944313).

It is not a de Polignac number, because 221944281 - 2⁵ = 221944249 is a prime.

It is a super-2 number, since 2×221944281² = 98518527737213922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221944201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3495 + ... + 21356.

It is an arithmetic number, because the mean of its divisors is an integer number (20005860).

Almost surely, 2^221944281 is an apocalyptic number.

It is an amenable number.

221944281 is a deficient number, since it is larger than the sum of its proper divisors (98149479).

221944281 is a wasteful number, since it uses less digits than its factorization.

221944281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25096.

The product of its digits is 9216, while the sum is 33.

The square root of 221944281 is about 14897.7945012005. The cubic root of 221944281 is about 605.4542325637.

The spelling of 221944281 in words is "two hundred twenty-one million, nine hundred forty-four thousand, two hundred eighty-one".