21175772016 has 160 divisors (see below), whose sum is σ = 66880719360. Its totient is φ = 5635473408.

The previous prime is 21175771993. The next prime is 21175772021. The reversal of 21175772016 is 61027757112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 534955 + ... + 573173.

It is an arithmetic number, because the mean of its divisors is an integer number (418004496).

Almost surely, 2^21175772016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21175772016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33440359680).

21175772016 is an abundant number, since it is smaller than the sum of its proper divisors (45704947344).

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

21175772016 is a wasteful number, since it uses less digits than its factorization.

21175772016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38351 (or 38345 counting only the distinct ones).

The product of its (nonzero) digits is 41160, while the sum is 39.

The spelling of 21175772016 in words is "twenty-one billion, one hundred seventy-five million, seven hundred seventy-two thousand, sixteen".