221213031231 has 8 divisors (see below), whose sum is σ = 294954747904. Its totient is φ = 147473334360.

The previous prime is 221213031227. The next prime is 221213031289. The reversal of 221213031231 is 132130312122.

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

It is not a de Polignac number, because 221213031231 - 2² = 221213031227 is a prime.

It is a super-2 number, since 2×221213031231² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221213031198 and 221213031207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221213031931) 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, 227641 + ... + 703026.

It is an arithmetic number, because the mean of its divisors is an integer number (36869343488).

Almost surely, 2^221213031231 is an apocalyptic number.

221213031231 is a deficient number, since it is larger than the sum of its proper divisors (73741716673).

221213031231 is an equidigital number, since it uses as much as digits as its factorization.

221213031231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1009901.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 221213031231 its reverse (132130312122), we get a palindrome (353343343353).

The spelling of 221213031231 in words is "two hundred twenty-one billion, two hundred thirteen million, thirty-one thousand, two hundred thirty-one".