1287987 has 4 divisors (see below), whose sum is σ = 1717320. Its totient is φ = 858656.

The previous prime is 1287983. The next prime is 1287989. The reversal of 1287987 is 7897821.

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

It is a cyclic number.

It is not a de Polignac number, because 1287987 - 2² = 1287983 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1287983) 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, 214662 + ... + 214667.

It is an arithmetic number, because the mean of its divisors is an integer number (429330).

2^1287987 is an apocalyptic number.

1287987 is a deficient number, since it is larger than the sum of its proper divisors (429333).

1287987 is an equidigital number, since it uses as much as digits as its factorization.

1287987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429332.

The product of its digits is 56448, while the sum is 42.

The square root of 1287987 is about 1134.8951493420. The cubic root of 1287987 is about 108.8020704533.

The spelling of 1287987 in words is "one million, two hundred eighty-seven thousand, nine hundred eighty-seven".