1215278197 has 4 divisors (see below), whose sum is σ = 1388889376. Its totient is φ = 1041667020.

The previous prime is 1215278191. The next prime is 1215278203. The reversal of 1215278197 is 7918725121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7918725121 = 1657 ⋅4778953.

It is an interprime number because it is at equal distance from previous prime (1215278191) and next prime (1215278203).

It is a cyclic number.

It is not a de Polignac number, because 1215278197 - 2⁷ = 1215278069 is a prime.

It is a super-2 number, since 2×1215278197² = 2953802192207141618, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215278191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86805579 + ... + 86805592.

It is an arithmetic number, because the mean of its divisors is an integer number (347222344).

Almost surely, 2^1215278197 is an apocalyptic number.

It is an amenable number.

1215278197 is a deficient number, since it is larger than the sum of its proper divisors (173611179).

1215278197 is an equidigital number, since it uses as much as digits as its factorization.

1215278197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173611178.

The product of its digits is 70560, while the sum is 43.

The square root of 1215278197 is about 34860.8404517160. The cubic root of 1215278197 is about 1067.1494268642.

The spelling of 1215278197 in words is "one billion, two hundred fifteen million, two hundred seventy-eight thousand, one hundred ninety-seven".