18855693540 has 120 divisors (see below), whose sum is σ = 59227233912. Its totient is φ = 5021706240.

The previous prime is 18855693529. The next prime is 18855693547. The reversal of 18855693540 is 4539655881.

18855693540 is a `hidden beast` number, since 1 + 8 + 8 + 5 + 5 + 6 + 93 + 540 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5372303616 + 13483389924 = 73296^2 + 116118^2 .

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

It is not an unprimeable number, because it can be changed into a prime (18855693547) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1322932 + ... + 1337108.

Almost surely, 2^18855693540 is an apocalyptic number.

18855693540 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 18855693540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29613616956).

18855693540 is an abundant number, since it is smaller than the sum of its proper divisors (40371540372).

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

18855693540 is a wasteful number, since it uses less digits than its factorization.

18855693540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15019 (or 15008 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 54.

The spelling of 18855693540 in words is "eighteen billion, eight hundred fifty-five million, six hundred ninety-three thousand, five hundred forty".