21365656312 has 192 divisors, whose sum is σ = 55127116800. Its totient is φ = 7551878400.

The previous prime is 21365656307. The next prime is 21365656339.

21365656312 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5195137 + ... + 5199247.

It is an arithmetic number, because the mean of its divisors is an integer number (287120400).

Almost surely, 2^21365656312 is an apocalyptic number.

21365656312 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 21365656312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27563558400).

21365656312 is an abundant number, since it is smaller than the sum of its proper divisors (33761460488).

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

21365656312 is a wasteful number, since it uses less digits than its factorization.

21365656312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4218 (or 4203 counting only the distinct ones).

The product of its digits is 194400, while the sum is 40.

The spelling of 21365656312 in words is "twenty-one billion, three hundred sixty-five million, six hundred fifty-six thousand, three hundred twelve".