1287731 has 2 divisors, whose sum is σ = 1287732. Its totient is φ = 1287730.

The previous prime is 1287707. The next prime is 1287739. The reversal of 1287731 is 1377821.

It is a strong prime.

It is an emirp because it is prime and its reverse (1377821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1287731 - 2¹⁰ = 1286707 is a prime.

It is a super-2 number, since 2×1287731² = 3316502256722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1287694 and 1287703.

It is not a weakly prime, because it can be changed into another prime (1287739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643865 + 643866.

It is an arithmetic number, because the mean of its divisors is an integer number (643866).

2^1287731 is an apocalyptic number.

1287731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287731 is an equidigital number, since it uses as much as digits as its factorization.

1287731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2352, while the sum is 29.

The square root of 1287731 is about 1134.7823579876. The cubic root of 1287731 is about 108.7948614842.

The spelling of 1287731 in words is "one million, two hundred eighty-seven thousand, seven hundred thirty-one".