18661228280 has 16 divisors (see below), whose sum is σ = 41987763720. Its totient is φ = 7464491296.

The previous prime is 18661228217. The next prime is 18661228283. The reversal of 18661228280 is 8282216681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18661228283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233265314 + ... + 233265393.

Almost surely, 2^18661228280 is an apocalyptic number.

18661228280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18661228280 is an abundant number, since it is smaller than the sum of its proper divisors (23326535440).

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

18661228280 is a wasteful number, since it uses less digits than its factorization.

18661228280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466530718 (or 466530714 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 44.

The spelling of 18661228280 in words is "eighteen billion, six hundred sixty-one million, two hundred twenty-eight thousand, two hundred eighty".