18355440 has 40 divisors (see below), whose sum is σ = 56902608. Its totient is φ = 4894720.

The previous prime is 18355433. The next prime is 18355451. The reversal of 18355440 is 4455381.

It is a tau number, because it is divible by the number of its divisors (40).

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 = 18355398 and 18355407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38001 + ... + 38480.

Almost surely, 2^18355440 is an apocalyptic number.

18355440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18355440 is an abundant number, since it is smaller than the sum of its proper divisors (38547168).

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

18355440 is a wasteful number, since it uses less digits than its factorization.

18355440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76497 (or 76491 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

The square root of 18355440 is about 4284.3249176504. The cubic root of 18355440 is about 263.7879380600.

The spelling of 18355440 in words is "eighteen million, three hundred fifty-five thousand, four hundred forty".