1289731 has 2 divisors, whose sum is σ = 1289732. Its totient is φ = 1289730.

The previous prime is 1289713. The next prime is 1289747. The reversal of 1289731 is 1379821.

Together with previous prime (1289713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (1379821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1289731 - 2¹¹ = 1287683 is a prime.

It is a super-2 number, since 2×1289731² = 3326812104722, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1289693 and 1289702.

It is not a weakly prime, because it can be changed into another prime (1289711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644865 + 644866.

It is an arithmetic number, because the mean of its divisors is an integer number (644866).

2^1289731 is an apocalyptic number.

1289731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1289731 is an equidigital number, since it uses as much as digits as its factorization.

1289731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 31.

The square root of 1289731 is about 1135.6632423390. The cubic root of 1289731 is about 108.8511561535.

The spelling of 1289731 in words is "one million, two hundred eighty-nine thousand, seven hundred thirty-one".