21244890240 has 768 divisors, whose sum is σ = 90431078400. Its totient is φ = 4488929280.

The previous prime is 21244890193. The next prime is 21244890253. The reversal of 21244890240 is 4209844212.

It is a super-2 number, since 2×21244890240² (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 junction number, because it is equal to n+sod(n) for n = 21244890195 and 21244890204.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 28747791 + ... + 28748529.

It is an arithmetic number, because the mean of its divisors is an integer number (117748800).

Almost surely, 2^21244890240 is an apocalyptic number.

21244890240 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 21244890240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45215539200).

21244890240 is an abundant number, since it is smaller than the sum of its proper divisors (69186188160).

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

21244890240 is a wasteful number, since it uses less digits than its factorization.

21244890240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825 (or 810 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The spelling of 21244890240 in words is "twenty-one billion, two hundred forty-four million, eight hundred ninety thousand, two hundred forty".