2121806149 has 2 divisors, whose sum is σ = 2121806150. Its totient is φ = 2121806148.

The previous prime is 2121806131. The next prime is 2121806177. The reversal of 2121806149 is 9416081212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1062303649 + 1059502500 = 32593^2 + 32550^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121806149 - 2¹¹ = 2121804101 is a prime.

It is a super-2 number, since 2×2121806149² = 9004122667868420402, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121806119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060903074 + 1060903075.

It is an arithmetic number, because the mean of its divisors is an integer number (1060903075).

Almost surely, 2^2121806149 is an apocalyptic number.

It is an amenable number.

2121806149 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121806149 is an equidigital number, since it uses as much as digits as its factorization.

2121806149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 2121806149 is about 46063.0670819910. The cubic root of 2121806149 is about 1284.9963711687.

The spelling of 2121806149 in words is "two billion, one hundred twenty-one million, eight hundred six thousand, one hundred forty-nine".