2138648917 has 2 divisors, whose sum is σ = 2138648918. Its totient is φ = 2138648916.

The previous prime is 2138648833. The next prime is 2138648969. The reversal of 2138648917 is 7198468312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1311453796 + 827195121 = 36214^2 + 28761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2138648917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2138648117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069324458 + 1069324459.

It is an arithmetic number, because the mean of its divisors is an integer number (1069324459).

Almost surely, 2^2138648917 is an apocalyptic number.

It is an amenable number.

2138648917 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138648917 is an equidigital number, since it uses as much as digits as its factorization.

2138648917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 580608, while the sum is 49.

The square root of 2138648917 is about 46245.5286162889. The cubic root of 2138648917 is about 1288.3874884209.

The spelling of 2138648917 in words is "two billion, one hundred thirty-eight million, six hundred forty-eight thousand, nine hundred seventeen".