2145121673 has 2 divisors, whose sum is σ = 2145121674. Its totient is φ = 2145121672.

The previous prime is 2145121661. The next prime is 2145121691. The reversal of 2145121673 is 3761215412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1164993424 + 980128249 = 34132^2 + 31307^2 .

It is a cyclic number.

It is not a de Polignac number, because 2145121673 - 2⁶ = 2145121609 is a prime.

It is not a weakly prime, because it can be changed into another prime (2145121073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1072560836 + 1072560837.

It is an arithmetic number, because the mean of its divisors is an integer number (1072560837).

Almost surely, 2^2145121673 is an apocalyptic number.

It is an amenable number.

2145121673 is a deficient number, since it is larger than the sum of its proper divisors (1).

2145121673 is an equidigital number, since it uses as much as digits as its factorization.

2145121673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 32.

The square root of 2145121673 is about 46315.4582509987. The cubic root of 2145121673 is about 1289.6859746816.

The spelling of 2145121673 in words is "two billion, one hundred forty-five million, one hundred twenty-one thousand, six hundred seventy-three".