18821030400 has 420 divisors, whose sum is σ = 69948539562. Its totient is φ = 5016453120.

The previous prime is 18821030329. The next prime is 18821030401. The reversal of 18821030400 is 403012881.

18821030400 is a `hidden beast` number, since 18 + 8 + 210 + 30 + 400 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 16684372224 + 2136658176 = 129168^2 + 46224^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18821030401) by changing a digit.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 9330192 + ... + 9332208.

Almost surely, 2^18821030400 is an apocalyptic number.

18821030400 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 18821030400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34974269781).

18821030400 is an abundant number, since it is smaller than the sum of its proper divisors (51127509162).

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

18821030400 is an frugal number, since it uses more digits than its factorization.

18821030400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2063 (or 2027 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The spelling of 18821030400 in words is "eighteen billion, eight hundred twenty-one million, thirty thousand, four hundred".