21270729600 has 480 divisors, whose sum is σ = 79198614000. Its totient is φ = 5621391360.

The previous prime is 21270729587. The next prime is 21270729617. The reversal of 21270729600 is 692707212.

21270729600 is a `hidden beast` number, since 2 + 1 + 27 + 0 + 7 + 29 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 35510101 + ... + 35510699.

Almost surely, 2^21270729600 is an apocalyptic number.

21270729600 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 21270729600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39599307000).

21270729600 is an abundant number, since it is smaller than the sum of its proper divisors (57927884400).

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

21270729600 is a wasteful number, since it uses less digits than its factorization.

21270729600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772 (or 746 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The spelling of 21270729600 in words is "twenty-one billion, two hundred seventy million, seven hundred twenty-nine thousand, six hundred".