21317057632640 has 256 divisors, whose sum is σ = 63801781401600. Its totient is φ = 6616473722880.

The previous prime is 21317057632597. The next prime is 21317057632649. The reversal of 21317057632640 is 4623675071312.

It is a happy number.

It is a super-2 number, since 2×21317057632640² (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 (21317057632649) 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, 10872962 + ... + 12682878.

It is an arithmetic number, because the mean of its divisors is an integer number (249225708600).

Almost surely, 2^{21317057632640} is an apocalyptic number.

21317057632640 is a gapful number since it is divisible by the number (20) 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 21317057632640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31900890700800).

21317057632640 is an abundant number, since it is smaller than the sum of its proper divisors (42484723768960).

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

21317057632640 is a wasteful number, since it uses less digits than its factorization.

21317057632640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1810193 (or 1810181 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 47.

The spelling of 21317057632640 in words is "twenty-one trillion, three hundred seventeen billion, fifty-seven million, six hundred thirty-two thousand, six hundred forty".