21326616617812 has 48 divisors (see below), whose sum is σ = 42832267732800. Its totient is φ = 9201005596160.

The previous prime is 21326616617767. The next prime is 21326616617837. The reversal of 21326616617812 is 21871661662312.

It is a self number, because there is not a number n which added to its sum of digits gives 21326616617812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141565813 + ... + 141716380.

It is an arithmetic number, because the mean of its divisors is an integer number (892338911100).

Almost surely, 2^{21326616617812} is an apocalyptic number.

21326616617812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21326616617812 is an abundant number, since it is smaller than the sum of its proper divisors (21505651114988).

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

21326616617812 is a wasteful number, since it uses less digits than its factorization.

21326616617812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283282296 (or 283282294 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 52.

The spelling of 21326616617812 in words is "twenty-one trillion, three hundred twenty-six billion, six hundred sixteen million, six hundred seventeen thousand, eight hundred twelve".