21654268416 has 360 divisors, whose sum is σ = 69788470752. Its totient is φ = 6457651200.

The previous prime is 21654268399. The next prime is 21654268423. The reversal of 21654268416 is 61486245612.

It is a happy number.

21654268416 is a `hidden beast` number, since 2 + 1 + 6 + 542 + 68 + 41 + 6 = 666.

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 35 ways as a sum of consecutive naturals, for example, 39587055 + ... + 39587601.

Almost surely, 2^21654268416 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 21654268416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34894235376).

21654268416 is an abundant number, since it is smaller than the sum of its proper divisors (48134202336).

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

21654268416 is a wasteful number, since it uses less digits than its factorization.

21654268416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664 (or 634 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The spelling of 21654268416 in words is "twenty-one billion, six hundred fifty-four million, two hundred sixty-eight thousand, four hundred sixteen".