1215855413 has 2 divisors, whose sum is σ = 1215855414. Its totient is φ = 1215855412.

The previous prime is 1215855359. The next prime is 1215855437. The reversal of 1215855413 is 3145585121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1161582724 + 54272689 = 34082^2 + 7367^2 .

It is a cyclic number.

It is not a de Polignac number, because 1215855413 - 2¹⁰ = 1215854389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1215855493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607927706 + 607927707.

It is an arithmetic number, because the mean of its divisors is an integer number (607927707).

Almost surely, 2^1215855413 is an apocalyptic number.

It is an amenable number.

1215855413 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215855413 is an equidigital number, since it uses as much as digits as its factorization.

1215855413 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24000, while the sum is 35.

The square root of 1215855413 is about 34869.1183284006. The cubic root of 1215855413 is about 1067.3183534052.

The spelling of 1215855413 in words is "one billion, two hundred fifteen million, eight hundred fifty-five thousand, four hundred thirteen".