21616279256 has 96 divisors (see below), whose sum is σ = 48051889200. Its totient is φ = 9055622400.

The previous prime is 21616279253. The next prime is 21616279277. The reversal of 21616279256 is 65297261612.

It is a self number, because there is not a number n which added to its sum of digits gives 21616279256.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21616279253) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 13350815 + ... + 13352433.

Almost surely, 2^21616279256 is an apocalyptic number.

21616279256 is a gapful number since it is divisible by the number (26) 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 21616279256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24025944600).

21616279256 is an abundant number, since it is smaller than the sum of its proper divisors (26435609944).

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

21616279256 is a wasteful number, since it uses less digits than its factorization.

21616279256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2721 (or 2706 counting only the distinct ones).

The product of its digits is 544320, while the sum is 47.

The spelling of 21616279256 in words is "twenty-one billion, six hundred sixteen million, two hundred seventy-nine thousand, two hundred fifty-six".