21906643906224 has 960 divisors, whose sum is σ = 79893016519680. Its totient is φ = 5645321256960.

The previous prime is 21906643906153. The next prime is 21906643906253. The reversal of 21906643906224 is 42260934660912.

21906643906224 is a `hidden beast` number, since 2 + 1 + 9 + 0 + 6 + 6 + 4 + 3 + 9 + 0 + 622 + 4 = 666.

It is a super-2 number, since 2×21906643906224² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 35505095164 + ... + 35505095780.

It is an arithmetic number, because the mean of its divisors is an integer number (83221892208).

Almost surely, 2^{21906643906224} is an apocalyptic number.

21906643906224 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 21906643906224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39946508259840).

21906643906224 is an abundant number, since it is smaller than the sum of its proper divisors (57986372613456).

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

21906643906224 is a wasteful number, since it uses less digits than its factorization.

21906643906224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1400 (or 1382 counting only the distinct ones).

The product of its (nonzero) digits is 6718464, while the sum is 54.

The spelling of 21906643906224 in words is "twenty-one trillion, nine hundred six billion, six hundred forty-three million, nine hundred six thousand, two hundred twenty-four".