21250242320 has 80 divisors (see below), whose sum is σ = 49908555648. Its totient is φ = 8414208000.

The previous prime is 21250242287. The next prime is 21250242329. The reversal of 21250242320 is 2324205212.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21250242329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3350192 + ... + 3356528.

Almost surely, 2^21250242320 is an apocalyptic number.

21250242320 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 21250242320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24954277824).

21250242320 is an abundant number, since it is smaller than the sum of its proper divisors (28658313328).

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

21250242320 is a wasteful number, since it uses less digits than its factorization.

21250242320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6768 (or 6762 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

Adding to 21250242320 its reverse (2324205212), we get a palindrome (23574447532).

The spelling of 21250242320 in words is "twenty-one billion, two hundred fifty million, two hundred forty-two thousand, three hundred twenty".