221121231 has 8 divisors (see below), whose sum is σ = 295461504. Its totient is φ = 147097560.

The previous prime is 221121223. The next prime is 221121253. The reversal of 221121231 is 132121122.

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

It is not a de Polignac number, because 221121231 - 2³ = 221121223 is a prime.

It is a super-2 number, since 2×221121231² = 97789197597910722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221121231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121281) 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, 77515 + ... + 80316.

It is an arithmetic number, because the mean of its divisors is an integer number (36932688).

Almost surely, 2^221121231 is an apocalyptic number.

221121231 is a deficient number, since it is larger than the sum of its proper divisors (74340273).

221121231 is a wasteful number, since it uses less digits than its factorization.

221121231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158301.

The product of its digits is 48, while the sum is 15.

The square root of 221121231 is about 14870.1456280697. The cubic root of 221121231 is about 604.7048907938.

Adding to 221121231 its reverse (132121122), we get a palindrome (353242353).

It can be divided in two parts, 22 and 1121231, that added together give a triangular number (1121253 = T₁₄₉₇).

The spelling of 221121231 in words is "two hundred twenty-one million, one hundred twenty-one thousand, two hundred thirty-one".