1321866 has 64 divisors (see below), whose sum is σ = 3628800. Its totient is φ = 347328.

The previous prime is 1321847. The next prime is 1321867. The reversal of 1321866 is 6681231.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1321867) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4780 + ... + 5048.

It is an arithmetic number, because the mean of its divisors is an integer number (56700).

2^1321866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1321866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1814400).

1321866 is an abundant number, since it is smaller than the sum of its proper divisors (2306934).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1321866 is a wasteful number, since it uses less digits than its factorization.

1321866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 294 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 1321866 is about 1149.7243147816. The cubic root of 1321866 is about 109.7477968573.

It can be divided in two parts, 1321 and 866, that added together give a 7-th power (2187 = 3⁷).

The spelling of 1321866 in words is "one million, three hundred twenty-one thousand, eight hundred sixty-six".