1215220775 has 12 divisors (see below), whose sum is σ = 1595513952. Its totient is φ = 914989440.

The previous prime is 1215220759. The next prime is 1215220781. The reversal of 1215220775 is 5770225121.

It is not a de Polignac number, because 1215220775 - 2⁴ = 1215220759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1429247 + ... + 1430096.

It is an arithmetic number, because the mean of its divisors is an integer number (132959496).

Almost surely, 2^1215220775 is an apocalyptic number.

1215220775 is a deficient number, since it is larger than the sum of its proper divisors (380293177).

1215220775 is a wasteful number, since it uses less digits than its factorization.

1215220775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2859370 (or 2859365 counting only the distinct ones).

The product of its (nonzero) digits is 9800, while the sum is 32.

The square root of 1215220775 is about 34860.0168531227. The cubic root of 1215220775 is about 1067.1326189652.

Adding to 1215220775 its reverse (5770225121), we get a palindrome (6985445896).

The spelling of 1215220775 in words is "one billion, two hundred fifteen million, two hundred twenty thousand, seven hundred seventy-five".