1287651 has 4 divisors (see below), whose sum is σ = 1716872. Its totient is φ = 858432.

The previous prime is 1287623. The next prime is 1287661. The reversal of 1287651 is 1567821.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1287651 - 2¹³ = 1279459 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287661) 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, 214606 + ... + 214611.

It is an arithmetic number, because the mean of its divisors is an integer number (429218).

2^1287651 is an apocalyptic number.

1287651 is a deficient number, since it is larger than the sum of its proper divisors (429221).

1287651 is an equidigital number, since it uses as much as digits as its factorization.

1287651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429220.

The product of its digits is 3360, while the sum is 30.

The square root of 1287651 is about 1134.7471083902. The cubic root of 1287651 is about 108.7926084854.

The spelling of 1287651 in words is "one million, two hundred eighty-seven thousand, six hundred fifty-one".