18263905920 has 640 divisors, whose sum is σ = 72062963280. Its totient is φ = 4379443200.

The previous prime is 18263905901. The next prime is 18263905931. The reversal of 18263905920 is 2950936281.

18263905920 is a `hidden beast` number, since 1 + 8 + 2 + 639 + 0 + 5 + 9 + 2 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 2694855744 + 15569050176 = 51912^2 + 124776^2 .

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×18263905920² (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 a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 27630390 + ... + 27631050.

Almost surely, 2^18263905920 is an apocalyptic number.

18263905920 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 18263905920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36031481640).

18263905920 is an abundant number, since it is smaller than the sum of its proper divisors (53799057360).

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

18263905920 is a wasteful number, since it uses less digits than its factorization.

18263905920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 18263905920 in words is "eighteen billion, two hundred sixty-three million, nine hundred five thousand, nine hundred twenty".