1290866 has 4 divisors (see below), whose sum is σ = 1936302. Its totient is φ = 645432.

The previous prime is 1290857. The next prime is 1290869. The reversal of 1290866 is 6680921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6680921 = 13 ⋅513917.

It can be written as a sum of positive squares in only one way, i.e., 1256641 + 34225 = 1121^2 + 185^2 .

It is not an unprimeable number, because it can be changed into a prime (1290869) 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, 322715 + ... + 322718.

2^1290866 is an apocalyptic number.

1290866 is a deficient number, since it is larger than the sum of its proper divisors (645436).

1290866 is an equidigital number, since it uses as much as digits as its factorization.

1290866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645435.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1290866 is about 1136.1628404415. The cubic root of 1290866 is about 108.8830774969.

The spelling of 1290866 in words is "one million, two hundred ninety thousand, eight hundred sixty-six".