21961368000 has 1344 divisors, whose sum is σ = 96923473920. Its totient is φ = 4852224000.

The previous prime is 21961367999. The next prime is 21961368007. The reversal of 21961368000 is 86316912.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21961368007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 277991961 + ... + 277992039.

It is an arithmetic number, because the mean of its divisors is an integer number (72115680).

Almost surely, 2^21961368000 is an apocalyptic number.

21961368000 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 21961368000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48461736960).

21961368000 is an abundant number, since it is smaller than the sum of its proper divisors (74962105920).

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

21961368000 is a wasteful number, since it uses less digits than its factorization.

21961368000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The spelling of 21961368000 in words is "twenty-one billion, nine hundred sixty-one million, three hundred sixty-eight thousand".