18249840 has 320 divisors, whose sum is σ = 77137920. Its totient is φ = 3870720.

The previous prime is 18249817. The next prime is 18249841. The reversal of 18249840 is 4894281.

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 = 18249795 and 18249804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18249841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 257005 + ... + 257075.

It is an arithmetic number, because the mean of its divisors is an integer number (241056).

Almost surely, 2^18249840 is an apocalyptic number.

18249840 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 18249840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38568960).

18249840 is an abundant number, since it is smaller than the sum of its proper divisors (58888080).

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

18249840 is a wasteful number, since it uses less digits than its factorization.

18249840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 18249840 is about 4271.9831460342. The cubic root of 18249840 is about 263.2811019981.

It can be divided in two parts, 1824 and 9840, that added together give a square (11664 = 108²).

The spelling of 18249840 in words is "eighteen million, two hundred forty-nine thousand, eight hundred forty".