1218965597 has 4 divisors (see below), whose sum is σ = 1221610236. Its totient is φ = 1216320960.

The previous prime is 1218965581. The next prime is 1218965669. The reversal of 1218965597 is 7955698121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 721943161 + 497022436 = 26869^2 + 22294^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218965597 - 2⁴ = 1218965581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218965537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1321628 + ... + 1322549.

It is an arithmetic number, because the mean of its divisors is an integer number (305402559).

Almost surely, 2^1218965597 is an apocalyptic number.

It is an amenable number.

1218965597 is a deficient number, since it is larger than the sum of its proper divisors (2644639).

1218965597 is an equidigital number, since it uses as much as digits as its factorization.

1218965597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2644638.

The product of its digits is 1360800, while the sum is 53.

The square root of 1218965597 is about 34913.6878172444. The cubic root of 1218965597 is about 1068.2276528573.

The spelling of 1218965597 in words is "one billion, two hundred eighteen million, nine hundred sixty-five thousand, five hundred ninety-seven".