1982809 has 2 divisors, whose sum is σ = 1982810. Its totient is φ = 1982808.

The previous prime is 1982803. The next prime is 1982833. The reversal of 1982809 is 9082891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1968409 + 14400 = 1403^2 + 120^2 .

It is a cyclic number.

It is not a de Polignac number, because 1982809 - 2⁷ = 1982681 is a prime.

1982809 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1982803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 991404 + 991405.

It is an arithmetic number, because the mean of its divisors is an integer number (991405).

2^1982809 is an apocalyptic number.

It is an amenable number.

1982809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1982809 is an equidigital number, since it uses as much as digits as its factorization.

1982809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 1982809 is about 1408.1225088748. The cubic root of 1982809 is about 125.6300773506.

It can be divided in two parts, 19 and 82809, that added together give a palindrome (82828).

The spelling of 1982809 in words is "one million, nine hundred eighty-two thousand, eight hundred nine".