201220721231 has 2 divisors, whose sum is σ = 201220721232. Its totient is φ = 201220721230.

The previous prime is 201220721213. The next prime is 201220721239. The reversal of 201220721231 is 132127022102.

Together with previous prime (201220721213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201220721231 - 2²⁶ = 201153612367 is a prime.

It is a super-2 number, since 2×201220721231² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 201220721197 and 201220721206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201220721239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610360615 + 100610360616.

It is an arithmetic number, because the mean of its divisors is an integer number (100610360616).

Almost surely, 2^201220721231 is an apocalyptic number.

201220721231 is a deficient number, since it is larger than the sum of its proper divisors (1).

201220721231 is an equidigital number, since it uses as much as digits as its factorization.

201220721231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

Adding to 201220721231 its reverse (132127022102), we get a palindrome (333347743333).

The spelling of 201220721231 in words is "two hundred one billion, two hundred twenty million, seven hundred twenty-one thousand, two hundred thirty-one".