18416640 has 176 divisors, whose sum is σ = 64848960. Its totient is φ = 4423680.

The previous prime is 18416617. The next prime is 18416641. The reversal of 18416640 is 4661481.

It is a tau number, because it is divible by the number of its divisors (176).

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 = 18416598 and 18416607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18416641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168906 + ... + 169014.

It is an arithmetic number, because the mean of its divisors is an integer number (368460).

Almost surely, 2^18416640 is an apocalyptic number.

18416640 is a gapful number since it is divisible by the number (10) 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 18416640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32424480).

18416640 is an abundant number, since it is smaller than the sum of its proper divisors (46432320).

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

18416640 is a wasteful number, since it uses less digits than its factorization.

18416640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 18416640 is about 4291.4612895842. The cubic root of 18416640 is about 264.0807833588.

The spelling of 18416640 in words is "eighteen million, four hundred sixteen thousand, six hundred forty".