21255456116 has 12 divisors (see below), whose sum is σ = 39385109988.
Its totient is φ = 10002567552.
The previous prime is 21255456113. The next prime is 21255456151. The reversal of 21255456116 is 61165455212.
It can be written as a sum of positive squares in 2 ways, for example, as 7465651216 + 13789804900 = 86404^2 + 117430^2
It is a self number, because there is not a number n which added to its sum of digits gives 21255456116.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (21255456113) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156290051 + ... + 156290186.
It is an arithmetic number, because the mean of its divisors is an integer number (3282092499).
Almost surely, 221255456116 is an apocalyptic number.
It is an amenable number.
21255456116 is a deficient number, since it is larger than the sum of its proper divisors (18129653872).
21255456116 is a wasteful number, since it uses less digits than its factorization.
21255456116 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 312580258 (or 312580256 counting only the distinct ones).
The product of its digits is 72000, while the sum is 38.
The spelling of 21255456116 in words is "twenty-one billion, two hundred fifty-five million, four hundred fifty-six thousand, one hundred sixteen".