221039807281 has 4 divisors (see below), whose sum is σ = 225742781952. Its totient is φ = 216336832612.

The previous prime is 221039807279. The next prime is 221039807291. The reversal of 221039807281 is 182708930122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221039807281 - 2¹ = 221039807279 is a prime.

It is a super-2 number, since 2×221039807281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221039807291) 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, 2351487265 + ... + 2351487358.

It is an arithmetic number, because the mean of its divisors is an integer number (56435695488).

Almost surely, 2^221039807281 is an apocalyptic number.

It is an amenable number.

221039807281 is a deficient number, since it is larger than the sum of its proper divisors (4702974671).

221039807281 is an equidigital number, since it uses as much as digits as its factorization.

221039807281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4702974670.

The product of its (nonzero) digits is 96768, while the sum is 43.

The spelling of 221039807281 in words is "two hundred twenty-one billion, thirty-nine million, eight hundred seven thousand, two hundred eighty-one".