1387637920 has 96 divisors (see below), whose sum is σ = 3490615296. Its totient is φ = 519475200.

The previous prime is 1387637897. The next prime is 1387637921. The reversal of 1387637920 is 297367831.

It is a happy number.

It is a super-5 number, since 5×1387637920⁵ (a number of 47 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (1387637921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 518185 + ... + 520855.

It is an arithmetic number, because the mean of its divisors is an integer number (36360576).

Almost surely, 2^1387637920 is an apocalyptic number.

1387637920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1387637920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1745307648).

1387637920 is an abundant number, since it is smaller than the sum of its proper divisors (2102977376).

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

1387637920 is a wasteful number, since it uses less digits than its factorization.

1387637920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2894 (or 2886 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 46.

The square root of 1387637920 is about 37251.0123352373. The cubic root of 1387637920 is about 1115.3865069318.

The spelling of 1387637920 in words is "one billion, three hundred eighty-seven million, six hundred thirty-seven thousand, nine hundred twenty".