21002282856 has 64 divisors (see below), whose sum is σ = 58505155200. Its totient is φ = 6980903424.

The previous prime is 21002282801. The next prime is 21002282857. The reversal of 21002282856 is 65828220012.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21002282856.

It is not an unprimeable number, because it can be changed into a prime (21002282857) 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 15 ways as a sum of consecutive naturals, for example, 61476 + ... + 213971.

It is an arithmetic number, because the mean of its divisors is an integer number (914143050).

Almost surely, 2^21002282856 is an apocalyptic number.

It is an amenable number.

21002282856 is an abundant number, since it is smaller than the sum of its proper divisors (37502872344).

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

21002282856 is a wasteful number, since it uses less digits than its factorization.

21002282856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275815 (or 275805 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The spelling of 21002282856 in words is "twenty-one billion, two million, two hundred eighty-two thousand, eight hundred fifty-six".