21850189520 has 80 divisors (see below), whose sum is σ = 53043569280. Its totient is φ = 8354852352.

The previous prime is 21850189511. The next prime is 21850189523. The reversal of 21850189520 is 2598105812.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21850189523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4301222 + ... + 4306298.

It is an arithmetic number, because the mean of its divisors is an integer number (663044616).

Almost surely, 2^21850189520 is an apocalyptic number.

21850189520 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 21850189520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26521784640).

21850189520 is an abundant number, since it is smaller than the sum of its proper divisors (31193379760).

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

21850189520 is a wasteful number, since it uses less digits than its factorization.

21850189520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7452 (or 7446 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 41.

The spelling of 21850189520 in words is "twenty-one billion, eight hundred fifty million, one hundred eighty-nine thousand, five hundred twenty".