21449678080 has 144 divisors (see below), whose sum is σ = 53112268944. Its totient is φ = 8294236160.

The previous prime is 21449678053. The next prime is 21449678093. The reversal of 21449678080 is 8087694412.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 15888098304 + 5561579776 = 126048^2 + 74576^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5928432 + ... + 5932048.

It is an arithmetic number, because the mean of its divisors is an integer number (368835201).

Almost surely, 2^21449678080 is an apocalyptic number.

21449678080 is a gapful number since it is divisible by the number (20) 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 21449678080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26556134472).

21449678080 is an abundant number, since it is smaller than the sum of its proper divisors (31662590864).

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

21449678080 is a wasteful number, since it uses less digits than its factorization.

21449678080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3792 (or 3778 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 49.

The spelling of 21449678080 in words is "twenty-one billion, four hundred forty-nine million, six hundred seventy-eight thousand, eighty".