18966993840 has 240 divisors, whose sum is σ = 69014788128. Its totient is φ = 4649508864.

The previous prime is 18966993821. The next prime is 18966993863. The reversal of 18966993840 is 4839966981.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 508302 + ... + 544338.

Almost surely, 2^18966993840 is an apocalyptic number.

18966993840 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 18966993840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34507394064).

18966993840 is an abundant number, since it is smaller than the sum of its proper divisors (50047794288).

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

18966993840 is a wasteful number, since it uses less digits than its factorization.

18966993840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36116 (or 36107 counting only the distinct ones).

The product of its (nonzero) digits is 20155392, while the sum is 63.

The spelling of 18966993840 in words is "eighteen billion, nine hundred sixty-six million, nine hundred ninety-three thousand, eight hundred forty".