2131023221 has 2 divisors, whose sum is σ = 2131023222. Its totient is φ = 2131023220.

The previous prime is 2131023217. The next prime is 2131023233. The reversal of 2131023221 is 1223201312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2046567121 + 84456100 = 45239^2 + 9190^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131023221 - 2² = 2131023217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2131023221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2131023241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065511610 + 1065511611.

It is an arithmetic number, because the mean of its divisors is an integer number (1065511611).

Almost surely, 2^2131023221 is an apocalyptic number.

It is an amenable number.

2131023221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131023221 is an equidigital number, since it uses as much as digits as its factorization.

2131023221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 2131023221 is about 46163.0070619322. The cubic root of 2131023221 is about 1286.8543472888.

Adding to 2131023221 its reverse (1223201312), we get a palindrome (3354224533).

The spelling of 2131023221 in words is "two billion, one hundred thirty-one million, twenty-three thousand, two hundred twenty-one".