21221551021160 has 128 divisors (see below), whose sum is σ = 55388815200000. Its totient is φ = 7166763546624.

The previous prime is 21221551021157. The next prime is 21221551021193. The reversal of 21221551021160 is 6112015512212.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 262768466 + ... + 262849214.

It is an arithmetic number, because the mean of its divisors is an integer number (432725118750).

Almost surely, 2^{21221551021160} is an apocalyptic number.

21221551021160 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 21221551021160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27694407600000).

21221551021160 is an abundant number, since it is smaller than the sum of its proper divisors (34167264178840).

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

21221551021160 is a wasteful number, since it uses less digits than its factorization.

21221551021160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94843 (or 94839 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 29.

Adding to 21221551021160 its reverse (6112015512212), we get a palindrome (27333566533372).

The spelling of 21221551021160 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred fifty-one million, twenty-one thousand, one hundred sixty".