18266820 has 96 divisors (see below), whose sum is σ = 60117120. Its totient is φ = 4085760.

The previous prime is 18266797. The next prime is 18266827. The reversal of 18266820 is 2866281.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (18266827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7516 + ... + 9644.

It is an arithmetic number, because the mean of its divisors is an integer number (626220).

Almost surely, 2^18266820 is an apocalyptic number.

18266820 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 18266820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30058560).

18266820 is an abundant number, since it is smaller than the sum of its proper divisors (41850300).

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

18266820 is a wasteful number, since it uses less digits than its factorization.

18266820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2165 (or 2163 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 18266820 is about 4273.9700513691. The cubic root of 18266820 is about 263.3627306105.

It can be divided in two parts, 1826 and 6820, that added together give a triangular number (8646 = T₁₃₁).

The spelling of 18266820 in words is "eighteen million, two hundred sixty-six thousand, eight hundred twenty".