1313638618 has 4 divisors (see below), whose sum is σ = 1970457930. Its totient is φ = 656819308.

The previous prime is 1313638591. The next prime is 1313638621. The reversal of 1313638618 is 8168363131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8168363131 = 19 ⋅429913849.

It can be written as a sum of positive squares in only one way, i.e., 721835689 + 591802929 = 26867^2 + 24327^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328409653 + ... + 328409656.

Almost surely, 2^1313638618 is an apocalyptic number.

1313638618 is a deficient number, since it is larger than the sum of its proper divisors (656819312).

1313638618 is an equidigital number, since it uses as much as digits as its factorization.

1313638618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656819311.

The product of its digits is 62208, while the sum is 40.

The square root of 1313638618 is about 36244.1528801543. The cubic root of 1313638618 is about 1095.1963029421.

The spelling of 1313638618 in words is "one billion, three hundred thirteen million, six hundred thirty-eight thousand, six hundred eighteen".