21318277281312 has 192 divisors, whose sum is σ = 61867184762880. Its totient is φ = 6373689907200.

The previous prime is 21318277281253. The next prime is 21318277281319.

21318277281312 is nontrivially palindromic in base 10.

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

It is not an unprimeable number, because it can be changed into a prime (21318277281319) 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, 43269637 + ... + 43759547.

It is an arithmetic number, because the mean of its divisors is an integer number (322224920640).

Almost surely, 2^{21318277281312} is an apocalyptic number.

21318277281312 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 21318277281312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30933592381440).

21318277281312 is an abundant number, since it is smaller than the sum of its proper divisors (40548907481568).

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

21318277281312 is a wasteful number, since it uses less digits than its factorization.

21318277281312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490487 (or 490479 counting only the distinct ones).

The product of its digits is 451584, while the sum is 48.

The spelling of 21318277281312 in words is "twenty-one trillion, three hundred eighteen billion, two hundred seventy-seven million, two hundred eighty-one thousand, three hundred twelve".