16721961984 has 528 divisors, whose sum is σ = 60276256768. Its totient is φ = 4347592704.

The previous prime is 16721961979. The next prime is 16721962007. The reversal of 16721961984 is 48916912761.

16721961984 is a `hidden beast` number, since 1 + 6 + 7 + 2 + 19 + 619 + 8 + 4 = 666.

It is a super-3 number, since 3×16721961984³ (a number of 32 digits) contains 333 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 16721961984.

It is a congruent number.

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, 106509234 + ... + 106509390.

Almost surely, 2^16721961984 is an apocalyptic number.

16721961984 is a gapful number since it is divisible by the number (14) 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 16721961984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30138128384).

16721961984 is an abundant number, since it is smaller than the sum of its proper divisors (43554294784).

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

16721961984 is a wasteful number, since it uses less digits than its factorization.

16721961984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330 (or 309 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The spelling of 16721961984 in words is "sixteen billion, seven hundred twenty-one million, nine hundred sixty-one thousand, nine hundred eighty-four".