1289531 has 2 divisors, whose sum is σ = 1289532. Its totient is φ = 1289530.

The previous prime is 1289513. The next prime is 1289537. The reversal of 1289531 is 1359821.

Together with previous prime (1289513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1289531 is a prime.

It is a super-2 number, since 2×1289531² = 3325780399922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1289494 and 1289503.

It is not a weakly prime, because it can be changed into another prime (1289537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644765 + 644766.

It is an arithmetic number, because the mean of its divisors is an integer number (644766).

2^1289531 is an apocalyptic number.

1289531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1289531 is an equidigital number, since it uses as much as digits as its factorization.

1289531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 29.

The square root of 1289531 is about 1135.5751846531. The cubic root of 1289531 is about 108.8455293066.

The spelling of 1289531 in words is "one million, two hundred eighty-nine thousand, five hundred thirty-one".