1387691344 has 20 divisors (see below), whose sum is σ = 2895471796. Its totient is φ = 640472832.

The previous prime is 1387691341. The next prime is 1387691489. The reversal of 1387691344 is 4431967831.

It can be written as a sum of positive squares in 2 ways, for example, as 252810000 + 1134881344 = 15900^2 + 33688^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1387691294 and 1387691303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387691341) 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, 3335589 + ... + 3336004.

Almost surely, 2^1387691344 is an apocalyptic number.

It is an amenable number.

1387691344 is an abundant number, since it is smaller than the sum of its proper divisors (1507780452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1387691344 is a wasteful number, since it uses less digits than its factorization.

1387691344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6671614 (or 6671608 counting only the distinct ones).

The product of its digits is 435456, while the sum is 46.

The square root of 1387691344 is about 37251.7294095187. The cubic root of 1387691344 is about 1115.4008208589.

The spelling of 1387691344 in words is "one billion, three hundred eighty-seven million, six hundred ninety-one thousand, three hundred forty-four".