21947486480640 has 648 divisors, whose sum is σ = 88896728302200. Its totient is φ = 4984595546112.

The previous prime is 21947486480639. The next prime is 21947486480641. The reversal of 21947486480640 is 4608468474912.

21947486480640 is a `hidden beast` number, since 2 + 1 + 9 + 4 + 74 + 86 + 480 + 6 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21947486480639) and next prime (21947486480641).

It can be written as a sum of positive squares in 4 ways, for example, as 372724902144 + 21574761578496 = 610512^2 + 4644864^2 .

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (21947486480641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 88499536 + ... + 88747184.

Almost surely, 2^{21947486480640} is an apocalyptic number.

21947486480640 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 21947486480640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44448364151100).

21947486480640 is an abundant number, since it is smaller than the sum of its proper divisors (66949241821560).

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

21947486480640 is a wasteful number, since it uses less digits than its factorization.

21947486480640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247847 (or 247823 counting only the distinct ones).

The product of its (nonzero) digits is 74317824, while the sum is 63.

The spelling of 21947486480640 in words is "twenty-one trillion, nine hundred forty-seven billion, four hundred eighty-six million, four hundred eighty thousand, six hundred forty".