21161264071200 has 288 divisors, whose sum is σ = 75155466617280. Its totient is φ = 5129065267200.

The previous prime is 21161264071159. The next prime is 21161264071217. The reversal of 21161264071200 is 217046216112.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 150119152 + ... + 150260048.

It is an arithmetic number, because the mean of its divisors is an integer number (260956481310).

Almost surely, 2^{21161264071200} is an apocalyptic number.

21161264071200 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 21161264071200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37577733308640).

21161264071200 is an abundant number, since it is smaller than the sum of its proper divisors (53994202546080).

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

21161264071200 is a wasteful number, since it uses less digits than its factorization.

21161264071200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146620 (or 146607 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The spelling of 21161264071200 in words is "twenty-one trillion, one hundred sixty-one billion, two hundred sixty-four million, seventy-one thousand, two hundred".