21896064720 has 320 divisors, whose sum is σ = 76750087680. Its totient is φ = 5736960000.

The previous prime is 21896064703. The next prime is 21896064727. The reversal of 21896064720 is 2746069812.

It is a happy number.

21896064720 is a `hidden beast` number, since 2 + 18 + 9 + 606 + 4 + 7 + 20 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21896064727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 36432420 + ... + 36433020.

It is an arithmetic number, because the mean of its divisors is an integer number (239844024).

Almost surely, 2^21896064720 is an apocalyptic number.

21896064720 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 21896064720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38375043840).

21896064720 is an abundant number, since it is smaller than the sum of its proper divisors (54854022960).

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

21896064720 is a wasteful number, since it uses less digits than its factorization.

21896064720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891 (or 879 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 21896064720 in words is "twenty-one billion, eight hundred ninety-six million, sixty-four thousand, seven hundred twenty".