21571416672 has 96 divisors (see below), whose sum is σ = 61419939840. Its totient is φ = 6589555200.

The previous prime is 21571416667. The next prime is 21571416689. The reversal of 21571416672 is 27661417512.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×21571416672³ (a number of 32 digits) contains 333 as substring.

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 15 ways as a sum of consecutive naturals, for example, 111297 + ... + 235647.

It is an arithmetic number, because the mean of its divisors is an integer number (639791040).

Almost surely, 2^21571416672 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 21571416672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30709969920).

21571416672 is an abundant number, since it is smaller than the sum of its proper divisors (39848523168).

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

21571416672 is a wasteful number, since it uses less digits than its factorization.

21571416672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124516 (or 124508 counting only the distinct ones).

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

The spelling of 21571416672 in words is "twenty-one billion, five hundred seventy-one million, four hundred sixteen thousand, six hundred seventy-two".