1215215173 has 2 divisors, whose sum is σ = 1215215174. Its totient is φ = 1215215172.

The previous prime is 1215215149. The next prime is 1215215179. The reversal of 1215215173 is 3715125121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 964847844 + 250367329 = 31062^2 + 15823^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1215215173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1215215179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607607586 + 607607587.

It is an arithmetic number, because the mean of its divisors is an integer number (607607587).

Almost surely, 2^1215215173 is an apocalyptic number.

It is an amenable number.

1215215173 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215215173 is an equidigital number, since it uses as much as digits as its factorization.

1215215173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2100, while the sum is 28.

The square root of 1215215173 is about 34859.9365030976. The cubic root of 1215215173 is about 1067.1309791846.

The spelling of 1215215173 in words is "one billion, two hundred fifteen million, two hundred fifteen thousand, one hundred seventy-three".