17978236416 has 420 divisors, whose sum is σ = 62714180232. Its totient is φ = 5131413504.

The previous prime is 17978236391. The next prime is 17978236433. The reversal of 17978236416 is 61463287971.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 18288661 + ... + 18289643.

Almost surely, 2^17978236416 is an apocalyptic number.

17978236416 is a gapful number since it is divisible by the number (16) 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 17978236416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31357090116).

17978236416 is an abundant number, since it is smaller than the sum of its proper divisors (44735943816).

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

17978236416 is an frugal number, since it uses more digits than its factorization.

17978236416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1033 (or 995 counting only the distinct ones).

The product of its digits is 3048192, while the sum is 54.

The spelling of 17978236416 in words is "seventeen billion, nine hundred seventy-eight million, two hundred thirty-six thousand, four hundred sixteen".