1287005 has 4 divisors (see below), whose sum is σ = 1544412. Its totient is φ = 1029600.

The previous prime is 1286983. The next prime is 1287007. The reversal of 1287005 is 5007821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 850084 + 436921 = 922^2 + 661^2 .

It is not a de Polignac number, because 1287005 - 2⁶ = 1286941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287007) 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, 128696 + ... + 128705.

It is an arithmetic number, because the mean of its divisors is an integer number (386103).

2^1287005 is an apocalyptic number.

It is an amenable number.

1287005 is a deficient number, since it is larger than the sum of its proper divisors (257407).

1287005 is an equidigital number, since it uses as much as digits as its factorization.

1287005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257406.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 1287005 is about 1134.4624277604. The cubic root of 1287005 is about 108.7744121001.

The spelling of 1287005 in words is "one million, two hundred eighty-seven thousand, five".