21408047232 has 768 divisors, whose sum is σ = 75754828800. Its totient is φ = 5264179200.

The previous prime is 21408047183. The next prime is 21408047237. The reversal of 21408047232 is 23274080412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21408047193 and 21408047202.

It is not an unprimeable number, because it can be changed into a prime (21408047237) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 301521757 + ... + 301521827.

It is an arithmetic number, because the mean of its divisors is an integer number (98639100).

Almost surely, 2^21408047232 is an apocalyptic number.

21408047232 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 21408047232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37877414400).

21408047232 is an abundant number, since it is smaller than the sum of its proper divisors (54346781568).

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

21408047232 is a wasteful number, since it uses less digits than its factorization.

21408047232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 33.

The spelling of 21408047232 in words is "twenty-one billion, four hundred eight million, forty-seven thousand, two hundred thirty-two".