21754547840 has 128 divisors (see below), whose sum is σ = 53511321600. Its totient is φ = 8452907008.

The previous prime is 21754547827. The next prime is 21754547891. The reversal of 21754547840 is 4874545712.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (47).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 4118321 + ... + 4123599.

It is an arithmetic number, because the mean of its divisors is an integer number (418057200).

Almost surely, 2^21754547840 is an apocalyptic number.

21754547840 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 21754547840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26755660800).

21754547840 is an abundant number, since it is smaller than the sum of its proper divisors (31756773760).

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

21754547840 is a wasteful number, since it uses less digits than its factorization.

21754547840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5482 (or 5470 counting only the distinct ones).

The product of its (nonzero) digits is 1254400, while the sum is 47.

The spelling of 21754547840 in words is "twenty-one billion, seven hundred fifty-four million, five hundred forty-seven thousand, eight hundred forty".