1387131408 has 60 divisors (see below), whose sum is σ = 4180665580. Its totient is φ = 426809088.

The previous prime is 1387131407. The next prime is 1387131419. The reversal of 1387131408 is 8041317831.

It can be written as a sum of positive squares in 2 ways, for example, as 107495424 + 1279635984 = 10368^2 + 35772^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1387131401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 368623 + ... + 372366.

Almost surely, 2^1387131408 is an apocalyptic number.

1387131408 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1387131408 is an abundant number, since it is smaller than the sum of its proper divisors (2793534172).

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

1387131408 is a wasteful number, since it uses less digits than its factorization.

1387131408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741016 (or 741007 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1387131408 is about 37244.2130806921. The cubic root of 1387131408 is about 1115.2507785846.

The spelling of 1387131408 in words is "one billion, three hundred eighty-seven million, one hundred thirty-one thousand, four hundred eight".