21113204221660 has 24 divisors (see below), whose sum is σ = 44340111219600. Its totient is φ = 8444827906944.

The previous prime is 21113204221631. The next prime is 21113204221787. The reversal of 21113204221660 is 6612240231112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27979710 + ... + 28724389.

It is an arithmetic number, because the mean of its divisors is an integer number (1847504634150).

Almost surely, 2^{21113204221660} is an apocalyptic number.

21113204221660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113204221660 is an abundant number, since it is smaller than the sum of its proper divisors (23226906997940).

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

21113204221660 is a wasteful number, since it uses less digits than its factorization.

21113204221660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56722725 (or 56722723 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

Adding to 21113204221660 its reverse (6612240231112), we get a palindrome (27725444452772).

The spelling of 21113204221660 in words is "twenty-one trillion, one hundred thirteen billion, two hundred four million, two hundred twenty-one thousand, six hundred sixty".