18853451820 has 144 divisors (see below), whose sum is σ = 65460403008. Its totient is φ = 4302650880.

The previous prime is 18853451779. The next prime is 18853451833. The reversal of 18853451820 is 2815435881.

18853451820 is a `hidden beast` number, since 1 + 8 + 85 + 34 + 518 + 20 = 666.

It is a super-2 number, since 2×18853451820² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 821542 + ... + 844178.

It is an arithmetic number, because the mean of its divisors is an integer number (454586132).

Almost surely, 2^18853451820 is an apocalyptic number.

18853451820 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 18853451820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32730201504).

18853451820 is an abundant number, since it is smaller than the sum of its proper divisors (46606951188).

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

18853451820 is a wasteful number, since it uses less digits than its factorization.

18853451820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23320 (or 23315 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 45.

The spelling of 18853451820 in words is "eighteen billion, eight hundred fifty-three million, four hundred fifty-one thousand, eight hundred twenty".