2131222311721 has 2 divisors, whose sum is σ = 2131222311722. Its totient is φ = 2131222311720.

The previous prime is 2131222311709. The next prime is 2131222311727. The reversal of 2131222311721 is 1271132221312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2061650864025 + 69571447696 = 1435845^2 + 263764^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131222311721 - 2²¹ = 2131220214569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2131222311721.

It is not a weakly prime, because it can be changed into another prime (2131222311727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065611155860 + 1065611155861.

It is an arithmetic number, because the mean of its divisors is an integer number (1065611155861).

Almost surely, 2^{2131222311721} is an apocalyptic number.

It is an amenable number.

2131222311721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131222311721 is an equidigital number, since it uses as much as digits as its factorization.

2131222311721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 28.

The spelling of 2131222311721 in words is "two trillion, one hundred thirty-one billion, two hundred twenty-two million, three hundred eleven thousand, seven hundred twenty-one".