18515278080 has 864 divisors, whose sum is σ = 75621786240. Its totient is φ = 4299816960.

The previous prime is 18515278079. The next prime is 18515278081. The reversal of 18515278080 is 8087251581.

It is an interprime number because it is at equal distance from previous prime (18515278079) and next prime (18515278081).

It is a tau number, because it is divible by the number of its divisors (864).

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

It is not an unprimeable number, because it can be changed into a prime (18515278081) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 76826760 + ... + 76827000.

Almost surely, 2^18515278080 is an apocalyptic number.

18515278080 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 18515278080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37810893120).

18515278080 is an abundant number, since it is smaller than the sum of its proper divisors (57106508160).

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

18515278080 is a wasteful number, since it uses less digits than its factorization.

18515278080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 179200, while the sum is 45.

The spelling of 18515278080 in words is "eighteen billion, five hundred fifteen million, two hundred seventy-eight thousand, eighty".