21221365055160 has 256 divisors, whose sum is σ = 67924258905600. Its totient is φ = 5285559910400.

The previous prime is 21221365055141. The next prime is 21221365055173. The reversal of 21221365055160 is 6155056312212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 179234380 + ... + 179352740.

It is an arithmetic number, because the mean of its divisors is an integer number (265329136350).

Almost surely, 2^{21221365055160} is an apocalyptic number.

21221365055160 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 21221365055160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33962129452800).

21221365055160 is an abundant number, since it is smaller than the sum of its proper divisors (46702893850440).

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

21221365055160 is a wasteful number, since it uses less digits than its factorization.

21221365055160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119062 (or 119058 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 39.

The spelling of 21221365055160 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred sixty-five million, fifty-five thousand, one hundred sixty".