221131231001 has 2 divisors, whose sum is σ = 221131231002. Its totient is φ = 221131231000.

The previous prime is 221131230953. The next prime is 221131231127. The reversal of 221131231001 is 100132131122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189952147225 + 31179083776 = 435835^2 + 176576^2 .

It is a cyclic number.

It is not a de Polignac number, because 221131231001 - 2³⁰ = 220057489177 is a prime.

It is not a weakly prime, because it can be changed into another prime (221131234001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110565615500 + 110565615501.

It is an arithmetic number, because the mean of its divisors is an integer number (110565615501).

Almost surely, 2^221131231001 is an apocalyptic number.

It is an amenable number.

221131231001 is a deficient number, since it is larger than the sum of its proper divisors (1).

221131231001 is an equidigital number, since it uses as much as digits as its factorization.

221131231001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 221131231001 its reverse (100132131122), we get a palindrome (321263362123).

The spelling of 221131231001 in words is "two hundred twenty-one billion, one hundred thirty-one million, two hundred thirty-one thousand, one".