221256231 has 8 divisors (see below), whose sum is σ = 337152384. Its totient is φ = 126432120.

The previous prime is 221256229. The next prime is 221256271. The reversal of 221256231 is 132652122.

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

It is not a de Polignac number, because 221256231 - 2¹ = 221256229 is a prime.

It is a super-2 number, since 2×221256231² = 97908639512650722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221256221) 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, 5267985 + ... + 5268026.

It is an arithmetic number, because the mean of its divisors is an integer number (42144048).

Almost surely, 2^221256231 is an apocalyptic number.

221256231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221256231 is a deficient number, since it is larger than the sum of its proper divisors (115896153).

221256231 is a wasteful number, since it uses less digits than its factorization.

221256231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10536021.

The product of its digits is 1440, while the sum is 24.

The square root of 221256231 is about 14874.6842319425. The cubic root of 221256231 is about 604.8279282065.

The spelling of 221256231 in words is "two hundred twenty-one million, two hundred fifty-six thousand, two hundred thirty-one".