21450609600 has 672 divisors, whose sum is σ = 86100489216. Its totient is φ = 4568678400.

The previous prime is 21450609563. The next prime is 21450609601. The reversal of 21450609600 is 690605412.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×21450609600² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450609601) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 31684462 + ... + 31685138.

It is an arithmetic number, because the mean of its divisors is an integer number (128125728).

Almost surely, 2^21450609600 is an apocalyptic number.

21450609600 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 21450609600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43050244608).

21450609600 is an abundant number, since it is smaller than the sum of its proper divisors (64649879616).

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

21450609600 is a wasteful number, since it uses less digits than its factorization.

21450609600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 773 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The spelling of 21450609600 in words is "twenty-one billion, four hundred fifty million, six hundred nine thousand, six hundred".