2121643723 has 2 divisors, whose sum is σ = 2121643724. Its totient is φ = 2121643722.

The previous prime is 2121643703. The next prime is 2121643753. The reversal of 2121643723 is 3273461212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121643723 - 2⁵ = 2121643691 is a prime.

It is not a weakly prime, because it can be changed into another prime (2121643703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060821861 + 1060821862.

It is an arithmetic number, because the mean of its divisors is an integer number (1060821862).

Almost surely, 2^2121643723 is an apocalyptic number.

2121643723 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121643723 is an equidigital number, since it uses as much as digits as its factorization.

2121643723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 31.

The square root of 2121643723 is about 46061.3039654763. The cubic root of 2121643723 is about 1284.9635811568.

The spelling of 2121643723 in words is "two billion, one hundred twenty-one million, six hundred forty-three thousand, seven hundred twenty-three".