21919616400 has 960 divisors, whose sum is σ = 87998939136. Its totient is φ = 4595712000.

The previous prime is 21919616363. The next prime is 21919616401. The reversal of 21919616400 is 461691912.

It is not an unprimeable number, because it can be changed into a prime (21919616401) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 159997132 + ... + 159997268.

Almost surely, 2^21919616400 is an apocalyptic number.

21919616400 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 21919616400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43999469568).

21919616400 is an abundant number, since it is smaller than the sum of its proper divisors (66079322736).

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

21919616400 is a wasteful number, since it uses less digits than its factorization.

21919616400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240 (or 229 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 39.

The spelling of 21919616400 in words is "twenty-one billion, nine hundred nineteen million, six hundred sixteen thousand, four hundred".