1251866 has 24 divisors (see below), whose sum is σ = 2362080. Its totient is φ = 487080.

The previous prime is 1251857. The next prime is 1251869. The reversal of 1251866 is 6681521.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1325 + ... + 2063.

It is an arithmetic number, because the mean of its divisors is an integer number (98420).

2^1251866 is an apocalyptic number.

1251866 is a deficient number, since it is larger than the sum of its proper divisors (1110214).

1251866 is a wasteful number, since it uses less digits than its factorization.

1251866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 759 counting only the distinct ones).

The product of its digits is 2880, while the sum is 29.

The square root of 1251866 is about 1118.8681781157. The cubic root of 1251866 is about 107.7753101863.

It can be divided in two parts, 125 and 1866, that added together give a palindrome (1991).

The spelling of 1251866 in words is "one million, two hundred fifty-one thousand, eight hundred sixty-six".