1215125617 has 2 divisors, whose sum is σ = 1215125618. Its totient is φ = 1215125616.

The previous prime is 1215125603. The next prime is 1215125669. The reversal of 1215125617 is 7165215121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1211109601 + 4016016 = 34801^2 + 2004^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1215125617 is a prime.

It is not a weakly prime, because it can be changed into another prime (1215125687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607562808 + 607562809.

It is an arithmetic number, because the mean of its divisors is an integer number (607562809).

Almost surely, 2^1215125617 is an apocalyptic number.

It is an amenable number.

1215125617 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215125617 is an equidigital number, since it uses as much as digits as its factorization.

1215125617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 31.

The square root of 1215125617 is about 34858.6519676249. The cubic root of 1215125617 is about 1067.1047642580.

The spelling of 1215125617 in words is "one billion, two hundred fifteen million, one hundred twenty-five thousand, six hundred seventeen".