1215766117 has 2 divisors, whose sum is σ = 1215766118. Its totient is φ = 1215766116.

The previous prime is 1215766073. The next prime is 1215766127. The reversal of 1215766117 is 7116675121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1214452801 + 1313316 = 34849^2 + 1146^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1215766117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1215766127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607883058 + 607883059.

It is an arithmetic number, because the mean of its divisors is an integer number (607883059).

Almost surely, 2^1215766117 is an apocalyptic number.

It is an amenable number.

1215766117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215766117 is an equidigital number, since it uses as much as digits as its factorization.

1215766117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 37.

The square root of 1215766117 is about 34867.8378595519. The cubic root of 1215766117 is about 1067.2922237652.

The spelling of 1215766117 in words is "one billion, two hundred fifteen million, seven hundred sixty-six thousand, one hundred seventeen".