21647480400 has 1440 divisors, whose sum is σ = 102758423040. Its totient is φ = 4111810560.

The previous prime is 21647480363. The next prime is 21647480401. The reversal of 21647480400 is 408474612.

21647480400 is a `hidden beast` number, since 2 + 1 + 647 + 4 + 8 + 0 + 4 + 0 + 0 = 666.

It is a super-2 number, since 2×21647480400² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21647480401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 941194789 + ... + 941194811.

It is an arithmetic number, because the mean of its divisors is an integer number (71360016).

Almost surely, 2^21647480400 is an apocalyptic number.

21647480400 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 21647480400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51379211520).

21647480400 is an abundant number, since it is smaller than the sum of its proper divisors (81110942640).

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

21647480400 is a wasteful number, since it uses less digits than its factorization.

21647480400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The spelling of 21647480400 in words is "twenty-one billion, six hundred forty-seven million, four hundred eighty thousand, four hundred".