1387639136 has 24 divisors (see below), whose sum is σ = 2942062704. Its totient is φ = 640448640.

The previous prime is 1387639129. The next prime is 1387639147. The reversal of 1387639136 is 6319367831.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1667420 + ... + 1668251.

It is an arithmetic number, because the mean of its divisors is an integer number (122585946).

Almost surely, 2^1387639136 is an apocalyptic number.

1387639136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1387639136 is an abundant number, since it is smaller than the sum of its proper divisors (1554423568).

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

1387639136 is a wasteful number, since it uses less digits than its factorization.

1387639136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3335694 (or 3335686 counting only the distinct ones).

The product of its digits is 489888, while the sum is 47.

The square root of 1387639136 is about 37251.0286569378. The cubic root of 1387639136 is about 1115.3868327395.

The spelling of 1387639136 in words is "one billion, three hundred eighty-seven million, six hundred thirty-nine thousand, one hundred thirty-six".