2130121909 has 2 divisors, whose sum is σ = 2130121910. Its totient is φ = 2130121908.

The previous prime is 2130121883. The next prime is 2130121933. The reversal of 2130121909 is 9091210312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2130099409 + 22500 = 46153^2 + 150^2 .

It is a cyclic number.

It is not a de Polignac number, because 2130121909 - 2⁹ = 2130121397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2130121999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065060954 + 1065060955.

It is an arithmetic number, because the mean of its divisors is an integer number (1065060955).

Almost surely, 2^2130121909 is an apocalyptic number.

It is an amenable number.

2130121909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2130121909 is an equidigital number, since it uses as much as digits as its factorization.

2130121909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 2130121909 is about 46153.2437538251. The cubic root of 2130121909 is about 1286.6728975495.

The spelling of 2130121909 in words is "two billion, one hundred thirty million, one hundred twenty-one thousand, nine hundred nine".