18430820 has 48 divisors (see below), whose sum is σ = 40884480. Its totient is φ = 6965376.

The previous prime is 18430813. The next prime is 18430823. The reversal of 18430820 is 2803481.

It is a self number, because there is not a number n which added to its sum of digits gives 18430820.

It is not an unprimeable number, because it can be changed into a prime (18430823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47186 + ... + 47574.

It is an arithmetic number, because the mean of its divisors is an integer number (851760).

Almost surely, 2^18430820 is an apocalyptic number.

18430820 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 18430820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20442240).

18430820 is an abundant number, since it is smaller than the sum of its proper divisors (22453660).

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

18430820 is a wasteful number, since it uses less digits than its factorization.

18430820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524 (or 522 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 18430820 is about 4293.1130895890. The cubic root of 18430820 is about 264.1485428206.

The spelling of 18430820 in words is "eighteen million, four hundred thirty thousand, eight hundred twenty".