1705981 has 4 divisors (see below), whose sum is σ = 1710172. Its totient is φ = 1701792.

The previous prime is 1705973. The next prime is 1705997. The reversal of 1705981 is 1895071.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1229881 + 476100 = 1109^2 + 690^2 .

It is a cyclic number.

It is not a de Polignac number, because 1705981 - 2³ = 1705973 is a prime.

It is a super-2 number, since 2×1705981² = 5820742344722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1705931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1410 + ... + 2323.

It is an arithmetic number, because the mean of its divisors is an integer number (427543).

2^1705981 is an apocalyptic number.

It is an amenable number.

1705981 is a deficient number, since it is larger than the sum of its proper divisors (4191).

1705981 is an equidigital number, since it uses as much as digits as its factorization.

1705981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4190.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 1705981 is about 1306.1320760168. The cubic root of 1705981 is about 119.4881205257.

The spelling of 1705981 in words is "one million, seven hundred five thousand, nine hundred eighty-one".