2318137721 has 2 divisors, whose sum is σ = 2318137722. Its totient is φ = 2318137720.

The previous prime is 2318137711. The next prime is 2318137729. The reversal of 2318137721 is 1277318132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2317363321 + 774400 = 48139^2 + 880^2 .

It is a cyclic number.

It is not a de Polignac number, because 2318137721 - 2³⁰ = 1244395897 is a prime.

It is not a weakly prime, because it can be changed into another prime (2318137729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1159068860 + 1159068861.

It is an arithmetic number, because the mean of its divisors is an integer number (1159068861).

Almost surely, 2^2318137721 is an apocalyptic number.

It is an amenable number.

2318137721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2318137721 is an equidigital number, since it uses as much as digits as its factorization.

2318137721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14112, while the sum is 35.

The square root of 2318137721 is about 48147.0427025378. The cubic root of 2318137721 is about 1323.4668815105.

The spelling of 2318137721 in words is "two billion, three hundred eighteen million, one hundred thirty-seven thousand, seven hundred twenty-one".