221031331331 has 2 divisors, whose sum is σ = 221031331332. Its totient is φ = 221031331330.

The previous prime is 221031331307. The next prime is 221031331349. The reversal of 221031331331 is 133133130122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221031331331 - 2¹⁸ = 221031069187 is a prime.

It is a super-2 number, since 2×221031331331² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221031331297 and 221031331306.

It is not a weakly prime, because it can be changed into another prime (221031331831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110515665665 + 110515665666.

It is an arithmetic number, because the mean of its divisors is an integer number (110515665666).

Almost surely, 2^221031331331 is an apocalyptic number.

221031331331 is a deficient number, since it is larger than the sum of its proper divisors (1).

221031331331 is an equidigital number, since it uses as much as digits as its factorization.

221031331331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 23.

Adding to 221031331331 its reverse (133133130122), we get a palindrome (354164461453).

The spelling of 221031331331 in words is "two hundred twenty-one billion, thirty-one million, three hundred thirty-one thousand, three hundred thirty-one".