1280387 has 8 divisors (see below), whose sum is σ = 1347840. Its totient is φ = 1213960.

The previous prime is 1280371. The next prime is 1280399. The reversal of 1280387 is 7830821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1280387 - 2⁴ = 1280371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1280317) 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, 3962 + ... + 4272.

It is an arithmetic number, because the mean of its divisors is an integer number (168480).

2^1280387 is an apocalyptic number.

1280387 is a deficient number, since it is larger than the sum of its proper divisors (67453).

1280387 is a wasteful number, since it uses less digits than its factorization.

1280387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513.

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

The square root of 1280387 is about 1131.5418684256. The cubic root of 1280387 is about 108.5876460572.

The spelling of 1280387 in words is "one million, two hundred eighty thousand, three hundred eighty-seven".