21613464678 has 96 divisors (see below), whose sum is σ = 49408597728. Its totient is φ = 6261027840.

The previous prime is 21613464661. The next prime is 21613464701. The reversal of 21613464678 is 87646431612.

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 47 ways as a sum of consecutive naturals, for example, 2769550 + ... + 2777342.

It is an arithmetic number, because the mean of its divisors is an integer number (514672893).

Almost surely, 2^21613464678 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21613464678, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24704298864).

21613464678 is an abundant number, since it is smaller than the sum of its proper divisors (27795133050).

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

21613464678 is a wasteful number, since it uses less digits than its factorization.

21613464678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7910 (or 7879 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 48.

The spelling of 21613464678 in words is "twenty-one billion, six hundred thirteen million, four hundred sixty-four thousand, six hundred seventy-eight".