918440640 has 672 divisors, whose sum is σ = 3815242560. Its totient is φ = 207028224.

The previous prime is 918440629. The next prime is 918440651. The reversal of 918440640 is 46044819.

It is a happy number.

918440640 is a `hidden beast` number, since 9 + 1 + 8 + 4 + 4 + 0 + 640 = 666.

918440640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (918440629) and next prime (918440651).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 918440595 and 918440604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 24822702 + ... + 24822738.

Almost surely, 2^918440640 is an apocalyptic number.

918440640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 918440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1907621280).

918440640 is an abundant number, since it is smaller than the sum of its proper divisors (2896801920).

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

918440640 is a wasteful number, since it uses less digits than its factorization.

918440640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 918440640 is about 30305.7855862540. The cubic root of 918440640 is about 972.0390168761.

The spelling of 918440640 in words is "nine hundred eighteen million, four hundred forty thousand, six hundred forty".