21272768856 has 40 divisors (see below), whose sum is σ = 59583451620. Its totient is φ = 7090922736.

The previous prime is 21272768833. The next prime is 21272768857. The reversal of 21272768856 is 65886727212.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272768857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 16413526 + ... + 16414821.

Almost surely, 2^21272768856 is an apocalyptic number.

It is an amenable number.

21272768856 is an abundant number, since it is smaller than the sum of its proper divisors (38310682764).

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

21272768856 is a wasteful number, since it uses less digits than its factorization.

21272768856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32828365 (or 32828352 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 21272768856 in words is "twenty-one billion, two hundred seventy-two million, seven hundred sixty-eight thousand, eight hundred fifty-six".