21947745120 has 384 divisors, whose sum is σ = 84594585600. Its totient is φ = 4671240192.

The previous prime is 21947745067. The next prime is 21947745121. The reversal of 21947745120 is 2154774912.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21947745121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3763647 + ... + 3769473.

It is an arithmetic number, because the mean of its divisors is an integer number (220298400).

Almost surely, 2^21947745120 is an apocalyptic number.

21947745120 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 21947745120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42297292800).

21947745120 is an abundant number, since it is smaller than the sum of its proper divisors (62646840480).

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

21947745120 is a wasteful number, since it uses less digits than its factorization.

21947745120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5930 (or 5922 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 42.

The spelling of 21947745120 in words is "twenty-one billion, nine hundred forty-seven million, seven hundred forty-five thousand, one hundred twenty".