1287961 has 2 divisors, whose sum is σ = 1287962. Its totient is φ = 1287960.

The previous prime is 1287947. The next prime is 1287967. The reversal of 1287961 is 1697821.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1089936 + 198025 = 1044^2 + 445^2 .

It is a cyclic number.

It is not a de Polignac number, because 1287961 - 2¹¹ = 1285913 is a prime.

It is not a weakly prime, because it can be changed into another prime (1287967) 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, 643980 + 643981.

It is an arithmetic number, because the mean of its divisors is an integer number (643981).

2^1287961 is an apocalyptic number.

It is an amenable number.

1287961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287961 is an equidigital number, since it uses as much as digits as its factorization.

1287961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 1287961 is about 1134.8836944815. The cubic root of 1287961 is about 108.8013383360.

The spelling of 1287961 in words is "one million, two hundred eighty-seven thousand, nine hundred sixty-one".