918981 has 24 divisors (see below), whose sum is σ = 1572480. Its totient is φ = 506016.

The previous prime is 918971. The next prime is 918989. The reversal of 918981 is 189819.

It is not a de Polignac number, because 918981 - 2⁵ = 918949 is a prime.

It is a super-2 number, since 2×918981² = 1689052156722, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 918981.

It is not an unprimeable number, because it can be changed into a prime (918989) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1576 + ... + 2078.

It is an arithmetic number, because the mean of its divisors is an integer number (65520).

2⁹¹⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

918981 is a deficient number, since it is larger than the sum of its proper divisors (653499).

918981 is a wasteful number, since it uses less digits than its factorization.

918981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545 (or 542 counting only the distinct ones).

The product of its digits is 5184, while the sum is 36.

The square root of 918981 is about 958.6349670234. The cubic root of 918981 is about 97.2229610949. Note that the first 3 decimals are identical.

The spelling of 918981 in words is "nine hundred eighteen thousand, nine hundred eighty-one".