21947424240 has 160 divisors (see below), whose sum is σ = 79031655936. Its totient is φ = 4934292480.

The previous prime is 21947424217. The next prime is 21947424241. The reversal of 21947424240 is 4242474912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21947424241) 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 31 ways as a sum of consecutive naturals, for example, 4602 + ... + 209561.

Almost surely, 2^21947424240 is an apocalyptic number.

21947424240 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 21947424240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39515827968).

21947424240 is an abundant number, since it is smaller than the sum of its proper divisors (57084231696).

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

21947424240 is a wasteful number, since it uses less digits than its factorization.

21947424240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214247 (or 214241 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 39.

The spelling of 21947424240 in words is "twenty-one billion, nine hundred forty-seven million, four hundred twenty-four thousand, two hundred forty".