18227840 has 64 divisors (see below), whose sum is σ = 45900000. Its totient is φ = 6902784.

The previous prime is 18227831. The next prime is 18227849. The reversal of 18227840 is 4872281.

It is an interprime number because it is at equal distance from previous prime (18227831) and next prime (18227849).

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 18227797 and 18227806.

It is not an unprimeable number, because it can be changed into a prime (18227849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11411 + ... + 12909.

Almost surely, 2^18227840 is an apocalyptic number.

18227840 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 18227840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22950000).

18227840 is an abundant number, since it is smaller than the sum of its proper divisors (27672160).

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

18227840 is a wasteful number, since it uses less digits than its factorization.

18227840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537 (or 1525 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 18227840 is about 4269.4074530314. The cubic root of 18227840 is about 263.1752652113.

The spelling of 18227840 in words is "eighteen million, two hundred twenty-seven thousand, eight hundred forty".