2121253181 has 2 divisors, whose sum is σ = 2121253182. Its totient is φ = 2121253180.

The previous prime is 2121253171. The next prime is 2121253247. The reversal of 2121253181 is 1813521212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2067157156 + 54096025 = 45466^2 + 7355^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121253181 - 2⁶ = 2121253117 is a prime.

It is a super-2 number, since 2×2121253181² = 8999430115805237522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2121253181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121253171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060626590 + 1060626591.

It is an arithmetic number, because the mean of its divisors is an integer number (1060626591).

Almost surely, 2^2121253181 is an apocalyptic number.

It is an amenable number.

2121253181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121253181 is an equidigital number, since it uses as much as digits as its factorization.

2121253181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 26.

The square root of 2121253181 is about 46057.0643984178. The cubic root of 2121253181 is about 1284.8847330077.

Adding to 2121253181 its reverse (1813521212), we get a palindrome (3934774393).

The spelling of 2121253181 in words is "two billion, one hundred twenty-one million, two hundred fifty-three thousand, one hundred eighty-one".