918881 has 4 divisors (see below), whose sum is σ = 928452. Its totient is φ = 909312.

The previous prime is 918877. The next prime is 918889. The reversal of 918881 is 188819.

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 707281 + 211600 = 841^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 918881 - 2² = 918877 is a prime.

It is a super-2 number, since 2×918881² = 1688684584322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918889) 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, 4640 + ... + 4833.

It is an arithmetic number, because the mean of its divisors is an integer number (232113).

2⁹¹⁸⁸⁸¹ is an apocalyptic number.

It is an amenable number.

918881 is a deficient number, since it is larger than the sum of its proper divisors (9571).

918881 is an equidigital number, since it uses as much as digits as its factorization.

918881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9570.

The product of its digits is 4608, while the sum is 35.

The square root of 918881 is about 958.5828081079. The cubic root of 918881 is about 97.2194344900.

The spelling of 918881 in words is "nine hundred eighteen thousand, eight hundred eighty-one".