21680502144 has 384 divisors, whose sum is σ = 70033689600. Its totient is φ = 5819793408.

The previous prime is 21680502143. The next prime is 21680502191. The reversal of 21680502144 is 44120508612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21680502143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 112334112 + ... + 112334304.

It is an arithmetic number, because the mean of its divisors is an integer number (182379400).

Almost surely, 2^21680502144 is an apocalyptic number.

21680502144 is a gapful number since it is divisible by the number (24) 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 21680502144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35016844800).

21680502144 is an abundant number, since it is smaller than the sum of its proper divisors (48353187456).

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

21680502144 is a wasteful number, since it uses less digits than its factorization.

21680502144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 33.

The spelling of 21680502144 in words is "twenty-one billion, six hundred eighty million, five hundred two thousand, one hundred forty-four".