21671323240 has 256 divisors, whose sum is σ = 62879846400. Its totient is φ = 6542954496.

The previous prime is 21671323237. The next prime is 21671323241. The reversal of 21671323240 is 4232317612.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21671323241) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7505077 + ... + 7507963.

It is an arithmetic number, because the mean of its divisors is an integer number (245624400).

Almost surely, 2^21671323240 is an apocalyptic number.

21671323240 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 21671323240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31439923200).

21671323240 is an abundant number, since it is smaller than the sum of its proper divisors (41208523160).

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

21671323240 is a wasteful number, since it uses less digits than its factorization.

21671323240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3024 (or 3020 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 31.

The spelling of 21671323240 in words is "twenty-one billion, six hundred seventy-one million, three hundred twenty-three thousand, two hundred forty".