1387280 has 20 divisors (see below), whose sum is σ = 3225612. Its totient is φ = 554880.

The previous prime is 1387271. The next prime is 1387289. The reversal of 1387280 is 827831.

It is an interprime number because it is at equal distance from previous prime (1387271) and next prime (1387289).

It can be written as a sum of positive squares in 2 ways, for example, as 913936 + 473344 = 956^2 + 688^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8591 + ... + 8750.

2^1387280 is an apocalyptic number.

1387280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1387280 is an abundant number, since it is smaller than the sum of its proper divisors (1838332).

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

1387280 is a wasteful number, since it uses less digits than its factorization.

1387280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17354 (or 17348 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 1387280 is about 1177.8285104377. The cubic root of 1387280 is about 111.5290599716.

The spelling of 1387280 in words is "one million, three hundred eighty-seven thousand, two hundred eighty".