18538892820 has 216 divisors, whose sum is σ = 66739929984. Its totient is φ = 4237251264.

The previous prime is 18538892807. The next prime is 18538892861. The reversal of 18538892820 is 2829883581.

18538892820 is a `hidden beast` number, since 1 + 8 + 538 + 89 + 2 + 8 + 20 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 908449 + ... + 928631.

Almost surely, 2^18538892820 is an apocalyptic number.

18538892820 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 18538892820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33369964992).

18538892820 is an abundant number, since it is smaller than the sum of its proper divisors (48201037164).

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

18538892820 is an equidigital number, since it uses as much as digits as its factorization.

18538892820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20223 (or 20200 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 54.

The spelling of 18538892820 in words is "eighteen billion, five hundred thirty-eight million, eight hundred ninety-two thousand, eight hundred twenty".