21345528600 has 288 divisors, whose sum is σ = 79087460400. Its totient is φ = 5116108800.

The previous prime is 21345528583. The next prime is 21345528629. The reversal of 21345528600 is 682554312.

21345528600 is a `hidden beast` number, since 2 + 1 + 3 + 45 + 5 + 2 + 8 + 600 = 666.

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 71 ways as a sum of consecutive naturals, for example, 1756144 + ... + 1768256.

Almost surely, 2^21345528600 is an apocalyptic number.

21345528600 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 21345528600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39543730200).

21345528600 is an abundant number, since it is smaller than the sum of its proper divisors (57741931800).

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

21345528600 is a wasteful number, since it uses less digits than its factorization.

21345528600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12235 (or 12223 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

It can be divided in two parts, 21345 and 528600, that added together give a palindrome (549945).

The spelling of 21345528600 in words is "twenty-one billion, three hundred forty-five million, five hundred twenty-eight thousand, six hundred".