18805779720 has 896 divisors, whose sum is σ = 82410451200. Its totient is φ = 3748902912.

The previous prime is 18805779719. The next prime is 18805779743. The reversal of 18805779720 is 2797750881.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 50417454 + ... + 50417826.

It is an arithmetic number, because the mean of its divisors is an integer number (91975950).

Almost surely, 2^18805779720 is an apocalyptic number.

18805779720 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 18805779720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41205225600).

18805779720 is an abundant number, since it is smaller than the sum of its proper divisors (63604671480).

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

18805779720 is a wasteful number, since it uses less digits than its factorization.

18805779720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 1975680, while the sum is 54.

The spelling of 18805779720 in words is "eighteen billion, eight hundred five million, seven hundred seventy-nine thousand, seven hundred twenty".