21564333346512 has 160 divisors (see below), whose sum is σ = 62457566031360. Its totient is φ = 6353668200960.

The previous prime is 21564333346511. The next prime is 21564333346513.

21564333346512 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (21564333346511) and next prime (21564333346513).

It is a super-2 number, since 2×21564333346512² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21564333346511) 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, 28124743 + ... + 28881305.

It is an arithmetic number, because the mean of its divisors is an integer number (390359787696).

Almost surely, 2^{21564333346512} is an apocalyptic number.

21564333346512 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 21564333346512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31228783015680).

21564333346512 is an abundant number, since it is smaller than the sum of its proper divisors (40893232684848).

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

21564333346512 is a wasteful number, since it uses less digits than its factorization.

21564333346512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758081 (or 758075 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 48.

The spelling of 21564333346512 in words is "twenty-one trillion, five hundred sixty-four billion, three hundred thirty-three million, three hundred forty-six thousand, five hundred twelve".