21653049600 has 1728 divisors, whose sum is σ = 104748295680. Its totient is φ = 4299816960.

The previous prime is 21653049589. The next prime is 21653049637. The reversal of 21653049600 is 694035612.

It is a happy number.

21653049600 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 3 + 0 + 49 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

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 (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1273708792 + ... + 1273708808.

Almost surely, 2^21653049600 is an apocalyptic number.

21653049600 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 21653049600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52374147840).

21653049600 is an abundant number, since it is smaller than the sum of its proper divisors (83095246080).

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

21653049600 is an equidigital number, since it uses as much as digits as its factorization.

21653049600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The spelling of 21653049600 in words is "twenty-one billion, six hundred fifty-three million, forty-nine thousand, six hundred".