21771404160 has 384 divisors, whose sum is σ = 78765281280. Its totient is φ = 5105971200.

The previous prime is 21771404143. The next prime is 21771404189. The reversal of 21771404160 is 6140417712.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7200409 + ... + 7203431.

It is an arithmetic number, because the mean of its divisors is an integer number (205117920).

Almost surely, 2^21771404160 is an apocalyptic number.

21771404160 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 21771404160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39382640640).

21771404160 is an abundant number, since it is smaller than the sum of its proper divisors (56993877120).

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

21771404160 is a wasteful number, since it uses less digits than its factorization.

21771404160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3098 (or 3075 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 33.

The spelling of 21771404160 in words is "twenty-one billion, seven hundred seventy-one million, four hundred four thousand, one hundred sixty".