21945459600 has 225 divisors, whose sum is σ = 78856308993. Its totient is φ = 5845011840.

The previous prime is 21945459593. The next prime is 21945459617. The reversal of 21945459600 is 695454912.

The square root of 21945459600 is 148140.

It is a perfect power (a square), and thus also a powerful number.

21945459600 is a `hidden beast` number, since 2 + 1 + 9 + 4 + 54 + 596 + 0 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7900365456 + 14045094144 = 88884^2 + 118512^2 .

It is a tau number, because it is divible by the number of its divisors (225).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 44 ways as a sum of consecutive naturals, for example, 26664789 + ... + 26665611.

Almost surely, 2^21945459600 is an apocalyptic number.

21945459600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21945459600 is the 148140-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21945459600

21945459600 is an abundant number, since it is smaller than the sum of its proper divisors (56910849393).

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

21945459600 is an frugal number, since it uses more digits than its factorization.

21945459600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1676 (or 833 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 21945459600 in words is "twenty-one billion, nine hundred forty-five million, four hundred fifty-nine thousand, six hundred".