21020244168 has 128 divisors (see below), whose sum is σ = 65597091840. Its totient is φ = 5453184000.

The previous prime is 21020244109. The next prime is 21020244169. The reversal of 21020244168 is 86144202012.

It is not an unprimeable number, because it can be changed into a prime (21020244169) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1621633 + ... + 1634543.

It is an arithmetic number, because the mean of its divisors is an integer number (512477280).

Almost surely, 2^21020244168 is an apocalyptic number.

21020244168 is a gapful number since it is divisible by the number (28) 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 21020244168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32798545920).

21020244168 is an abundant number, since it is smaller than the sum of its proper divisors (44576847672).

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

21020244168 is a wasteful number, since it uses less digits than its factorization.

21020244168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13819 (or 13815 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The spelling of 21020244168 in words is "twenty-one billion, twenty million, two hundred forty-four thousand, one hundred sixty-eight".