21564733746512 has 160 divisors (see below), whose sum is σ = 46636287408000. Its totient is φ = 9578380032000.

The previous prime is 21564733746511. The next prime is 21564733746553.

It is a happy number.

21564733746512 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×21564733746512² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21564733746511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 415808039 + ... + 415859897.

It is an arithmetic number, because the mean of its divisors is an integer number (291476796300).

Almost surely, 2^{21564733746512} is an apocalyptic number.

21564733746512 is a gapful number since it is divisible by the number (22) 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 21564733746512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23318143704000).

21564733746512 is an abundant number, since it is smaller than the sum of its proper divisors (25071553661488).

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

21564733746512 is a wasteful number, since it uses less digits than its factorization.

21564733746512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52285 (or 52279 counting only the distinct ones).

The product of its digits is 25401600, while the sum is 56.

The spelling of 21564733746512 in words is "twenty-one trillion, five hundred sixty-four billion, seven hundred thirty-three million, seven hundred forty-six thousand, five hundred twelve".