916981 has 4 divisors (see below), whose sum is σ = 987532. Its totient is φ = 846432.

The previous prime is 916973. The next prime is 916999. The reversal of 916981 is 189619.

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 538756 + 378225 = 734^2 + 615^2 .

It is a cyclic number.

It is not a de Polignac number, because 916981 - 2³ = 916973 is a prime.

It is a super-2 number, since 2×916981² = 1681708308722, which contains 22 as substring.

916981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (916931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35256 + ... + 35281.

It is an arithmetic number, because the mean of its divisors is an integer number (246883).

2⁹¹⁶⁹⁸¹ is an apocalyptic number.

It is an amenable number.

916981 is a deficient number, since it is larger than the sum of its proper divisors (70551).

916981 is a wasteful number, since it uses less digits than its factorization.

916981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70550.

The product of its digits is 3888, while the sum is 34.

The square root of 916981 is about 957.5912489157. The cubic root of 916981 is about 97.1523803277.

The spelling of 916981 in words is "nine hundred sixteen thousand, nine hundred eighty-one".