21673809600 has 168 divisors, whose sum is σ = 71369243088. Its totient is φ = 5758464000.

The previous prime is 21673809583. The next prime is 21673809601. The reversal of 21673809600 is 690837612.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21673809601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1321450 + ... + 1337750.

Almost surely, 2^21673809600 is an apocalyptic number.

21673809600 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 21673809600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35684621544).

21673809600 is an abundant number, since it is smaller than the sum of its proper divisors (49695433488).

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

21673809600 is a wasteful number, since it uses less digits than its factorization.

21673809600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16603 (or 16588 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The spelling of 21673809600 in words is "twenty-one billion, six hundred seventy-three million, eight hundred nine thousand, six hundred".