17981993920 has 336 divisors, whose sum is σ = 49502251008. Its totient is φ = 6209280000.

The previous prime is 17981993893. The next prime is 17981993959. The reversal of 17981993920 is 2939918971.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 85222615 + ... + 85222825.

It is an arithmetic number, because the mean of its divisors is an integer number (147328128).

Almost surely, 2^17981993920 is an apocalyptic number.

17981993920 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 17981993920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24751125504).

17981993920 is an abundant number, since it is smaller than the sum of its proper divisors (31520257088).

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

17981993920 is a wasteful number, since it uses less digits than its factorization.

17981993920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352 (or 331 counting only the distinct ones).

The product of its (nonzero) digits is 2204496, while the sum is 58.

The spelling of 17981993920 in words is "seventeen billion, nine hundred eighty-one million, nine hundred ninety-three thousand, nine hundred twenty".