221505231 has 8 divisors (see below), whose sum is σ = 296665600. Its totient is φ = 147007512.

The previous prime is 221505227. The next prime is 221505253. The reversal of 221505231 is 132505122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221505231 - 2² = 221505227 is a prime.

It is a super-2 number, since 2×221505231² = 98129134720726722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221505198 and 221505207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221505281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164881 + ... + 166218.

It is an arithmetic number, because the mean of its divisors is an integer number (37083200).

Almost surely, 2^221505231 is an apocalyptic number.

221505231 is a deficient number, since it is larger than the sum of its proper divisors (75160369).

221505231 is a wasteful number, since it uses less digits than its factorization.

221505231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331325.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 221505231 is about 14883.0518039816. The cubic root of 221505231 is about 605.0547326573.

The spelling of 221505231 in words is "two hundred twenty-one million, five hundred five thousand, two hundred thirty-one".