221312313231 has 4 divisors (see below), whose sum is σ = 295083084312. Its totient is φ = 147541542152.

The previous prime is 221312313221. The next prime is 221312313331. The reversal of 221312313231 is 132313213122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221312313231 - 2⁵ = 221312313199 is a prime.

It is a super-2 number, since 2×221312313231² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221312313221) 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, 36885385536 + ... + 36885385541.

It is an arithmetic number, because the mean of its divisors is an integer number (73770771078).

Almost surely, 2^221312313231 is an apocalyptic number.

221312313231 is a deficient number, since it is larger than the sum of its proper divisors (73770771081).

221312313231 is an equidigital number, since it uses as much as digits as its factorization.

221312313231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73770771080.

The product of its digits is 1296, while the sum is 24.

Adding to 221312313231 its reverse (132313213122), we get a palindrome (353625526353).

The spelling of 221312313231 in words is "two hundred twenty-one billion, three hundred twelve million, three hundred thirteen thousand, two hundred thirty-one".