1387640 has 32 divisors (see below), whose sum is σ = 3160080. Its totient is φ = 548352.

The previous prime is 1387601. The next prime is 1387649. The reversal of 1387640 is 467831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4367 + ... + 4673.

2^1387640 is an apocalyptic number.

1387640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1387640 is an abundant number, since it is smaller than the sum of its proper divisors (1772440).

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

1387640 is a wasteful number, since it uses less digits than its factorization.

1387640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 1387640 is about 1177.9813241304. The cubic root of 1387640 is about 111.5387064234.

The spelling of 1387640 in words is "one million, three hundred eighty-seven thousand, six hundred forty".