21723159920 has 320 divisors, whose sum is σ = 65524377600. Its totient is φ = 6498938880.

The previous prime is 21723159919. The next prime is 21723159943. The reversal of 21723159920 is 2995132712.

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 63 ways as a sum of consecutive naturals, for example, 49483061 + ... + 49483499.

It is an arithmetic number, because the mean of its divisors is an integer number (204763680).

Almost surely, 2^21723159920 is an apocalyptic number.

21723159920 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 21723159920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32762188800).

21723159920 is an abundant number, since it is smaller than the sum of its proper divisors (43801217680).

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

21723159920 is a wasteful number, since it uses less digits than its factorization.

21723159920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 776 (or 770 counting only the distinct ones).

The product of its (nonzero) digits is 68040, while the sum is 41.

The spelling of 21723159920 in words is "twenty-one billion, seven hundred twenty-three million, one hundred fifty-nine thousand, nine hundred twenty".