18947291880 has 128 divisors (see below), whose sum is σ = 62706441600. Its totient is φ = 4541644800.

The previous prime is 18947291851. The next prime is 18947291899. The reversal of 18947291880 is 8819274981.

It is a self number, because there is not a number n which added to its sum of digits gives 18947291880.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36840 + ... + 198120.

It is an arithmetic number, because the mean of its divisors is an integer number (489894075).

Almost surely, 2^18947291880 is an apocalyptic number.

18947291880 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 18947291880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31353220800).

18947291880 is an abundant number, since it is smaller than the sum of its proper divisors (43759149720).

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

18947291880 is a wasteful number, since it uses less digits than its factorization.

18947291880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161395 (or 161391 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 57.

The spelling of 18947291880 in words is "eighteen billion, nine hundred forty-seven million, two hundred ninety-one thousand, eight hundred eighty".