21072261600 has 1296 divisors, whose sum is σ = 91662414480. Its totient is φ = 4512153600.

The previous prime is 21072261599. The next prime is 21072261611. The reversal of 21072261600 is 616227012.

21072261600 is a `hidden beast` number, since 21 + 0 + 7 + 22 + 616 + 0 + 0 = 666.

It is a super-3 number, since 3×21072261600³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 513957580 + ... + 513957620.

Almost surely, 2^21072261600 is an apocalyptic number.

21072261600 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 21072261600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45831207240).

21072261600 is an abundant number, since it is smaller than the sum of its proper divisors (70590152880).

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

21072261600 is a wasteful number, since it uses less digits than its factorization.

21072261600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

Adding to 21072261600 its reverse (616227012), we get a palindrome (21688488612).

The spelling of 21072261600 in words is "twenty-one billion, seventy-two million, two hundred sixty-one thousand, six hundred".