1387897920 has 84 divisors (see below), whose sum is σ = 4773800460. Its totient is φ = 370105344.

The previous prime is 1387897877. The next prime is 1387897943. The reversal of 1387897920 is 297987831.

It can be written as a sum of positive squares in 2 ways, for example, as 474891264 + 913006656 = 21792^2 + 30216^2 .

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 238075 + ... + 243834.

Almost surely, 2^1387897920 is an apocalyptic number.

1387897920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1387897920 is an abundant number, since it is smaller than the sum of its proper divisors (3385902540).

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

1387897920 is a wasteful number, since it uses less digits than its factorization.

1387897920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481932 (or 481919 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The square root of 1387897920 is about 37254.5020098243. The cubic root of 1387897920 is about 1115.4561654445.

The spelling of 1387897920 in words is "one billion, three hundred eighty-seven million, eight hundred ninety-seven thousand, nine hundred twenty".