981665 has 8 divisors (see below), whose sum is σ = 1247400. Its totient is φ = 739072.

The previous prime is 981653. The next prime is 981683. The reversal of 981665 is 566189.

It can be written as a sum of positive squares in 4 ways, for example, as 474721 + 506944 = 689^2 + 712^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 981665 - 2⁶ = 981601 is a prime.

It is a plaindrome in base 7.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5690 + ... + 5859.

It is an arithmetic number, because the mean of its divisors is an integer number (155925).

2⁹⁸¹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

981665 is a deficient number, since it is larger than the sum of its proper divisors (265735).

981665 is a wasteful number, since it uses less digits than its factorization.

981665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11571.

The product of its digits is 12960, while the sum is 35.

The square root of 981665 is about 990.7900887675. The cubic root of 981665 is about 99.3850595673.

The spelling of 981665 in words is "nine hundred eighty-one thousand, six hundred sixty-five".