1381993813 has 4 divisors (see below), whose sum is σ = 1414133248. Its totient is φ = 1349854380.

The previous prime is 1381993799. The next prime is 1381993817. The reversal of 1381993813 is 3183991831.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 1381993813 - 2²⁵ = 1348439381 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 (1381993817) 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, 16069653 + ... + 16069738.

It is an arithmetic number, because the mean of its divisors is an integer number (353533312).

Almost surely, 2^1381993813 is an apocalyptic number.

It is an amenable number.

1381993813 is a deficient number, since it is larger than the sum of its proper divisors (32139435).

1381993813 is an equidigital number, since it uses as much as digits as its factorization.

1381993813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32139434.

The product of its digits is 139968, while the sum is 46.

The square root of 1381993813 is about 37175.1773768465. The cubic root of 1381993813 is about 1113.8722033003.

The spelling of 1381993813 in words is "one billion, three hundred eighty-one million, nine hundred ninety-three thousand, eight hundred thirteen".