21666060336 has 80 divisors (see below), whose sum is σ = 57375077760. Its totient is φ = 7041047040.

The previous prime is 21666060313. The next prime is 21666060389. The reversal of 21666060336 is 63306066612.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21666060294 and 21666060303.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3891891 + ... + 3897453.

It is an arithmetic number, because the mean of its divisors is an integer number (717188472).

Almost surely, 2^21666060336 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21666060336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28687538880).

21666060336 is an abundant number, since it is smaller than the sum of its proper divisors (35709017424).

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

21666060336 is a wasteful number, since it uses less digits than its factorization.

21666060336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7594 (or 7588 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 39.

The spelling of 21666060336 in words is "twenty-one billion, six hundred sixty-six million, sixty thousand, three hundred thirty-six".