21315440000000 has 352 divisors, whose sum is σ = 54405282597120. Its totient is φ = 8343296000000.

The previous prime is 21315439999969. The next prime is 21315440000069. The reversal of 21315440000000 is 4451312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3759997166 + ... + 3760002834.

Almost surely, 2^{21315440000000} is an apocalyptic number.

21315440000000 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 21315440000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27202641298560).

21315440000000 is an abundant number, since it is smaller than the sum of its proper divisors (33089842597120).

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

21315440000000 is an frugal number, since it uses more digits than its factorization.

21315440000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5771 (or 5723 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21315440000000 its reverse (4451312), we get a palindrome (21315444451312).

The spelling of 21315440000000 in words is "twenty-one trillion, three hundred fifteen billion, four hundred forty million", and thus it is an aban number.