918840 has 128 divisors (see below), whose sum is σ = 3225600. Its totient is φ = 207360.

The previous prime is 918839. The next prime is 918857. The reversal of 918840 is 48819.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 918798 and 918807.

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 918840.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29625 + ... + 29655.

It is an arithmetic number, because the mean of its divisors is an integer number (25200).

2⁹¹⁸⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 918840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1612800).

918840 is an abundant number, since it is smaller than the sum of its proper divisors (2306760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

918840 is a wasteful number, since it uses less digits than its factorization.

918840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 918840 is about 958.5614221321. The cubic root of 918840 is about 97.2179885080.

918840 divided by its sum of digits (30) gives a triangular number (30628 = T₂₄₇).

The spelling of 918840 in words is "nine hundred eighteen thousand, eight hundred forty".