18009775872 has 504 divisors, whose sum is σ = 60910284288. Its totient is φ = 5262796800.

The previous prime is 18009775853. The next prime is 18009775891. The reversal of 18009775872 is 27857790081.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18009775853) and next prime (18009775891).

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 55 ways as a sum of consecutive naturals, for example, 63638643 + ... + 63638925.

Almost surely, 2^18009775872 is an apocalyptic number.

18009775872 is a gapful number since it is divisible by the number (12) 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 18009775872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30455142144).

18009775872 is an abundant number, since it is smaller than the sum of its proper divisors (42900508416).

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

18009775872 is an equidigital number, since it uses as much as digits as its factorization.

18009775872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 330 counting only the distinct ones).

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

It can be divided in two parts, 18009 and 775872, that added together give a square (793881 = 891²).

The spelling of 18009775872 in words is "eighteen billion, nine million, seven hundred seventy-five thousand, eight hundred seventy-two".