21120207264 has 288 divisors, whose sum is σ = 69544500480. Its totient is φ = 6024554496.

The previous prime is 21120207253. The next prime is 21120207293. The reversal of 21120207264 is 46270202112.

It is a tau number, because it is divible by the number of its divisors (288).

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 3340234 + ... + 3346550.

It is an arithmetic number, because the mean of its divisors is an integer number (241473960).

Almost surely, 2^21120207264 is an apocalyptic number.

21120207264 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 21120207264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34772250240).

21120207264 is an abundant number, since it is smaller than the sum of its proper divisors (48424293216).

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

21120207264 is a wasteful number, since it uses less digits than its factorization.

21120207264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6412 (or 6401 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

Adding to 21120207264 its reverse (46270202112), we get a palindrome (67390409376).

The spelling of 21120207264 in words is "twenty-one billion, one hundred twenty million, two hundred seven thousand, two hundred sixty-four".