1387131399 has 40 divisors (see below), whose sum is σ = 2114483712. Its totient is φ = 905981760.

The previous prime is 1387131391. The next prime is 1387131401. The reversal of 1387131399 is 9931317831.

1387131399 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1387131399 - 2³ = 1387131391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387131391) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1892037 + ... + 1892769.

Almost surely, 2^1387131399 is an apocalyptic number.

1387131399 is a deficient number, since it is larger than the sum of its proper divisors (727352313).

1387131399 is an equidigital number, since it uses as much as digits as its factorization.

1387131399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189 (or 1180 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 1387131399 is about 37244.2129598680. The cubic root of 1387131399 is about 1115.2507761726.

The spelling of 1387131399 in words is "one billion, three hundred eighty-seven million, one hundred thirty-one thousand, three hundred ninety-nine".