981805 has 8 divisors (see below), whose sum is σ = 1285344. Its totient is φ = 714000.

The previous prime is 981797. The next prime is 981809. The reversal of 981805 is 508189.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 981805 - 2³ = 981797 is a prime.

It is a Duffinian number.

981805 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981809) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8871 + ... + 8980.

It is an arithmetic number, because the mean of its divisors is an integer number (160668).

2⁹⁸¹⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

981805 is a deficient number, since it is larger than the sum of its proper divisors (303539).

981805 is a wasteful number, since it uses less digits than its factorization.

981805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17867.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 981805 is about 990.8607369353. The cubic root of 981805 is about 99.3897839376.

The spelling of 981805 in words is "nine hundred eighty-one thousand, eight hundred five".