21894813340645 has 32 divisors (see below), whose sum is σ = 31710204352512. Its totient is φ = 14187799678272.

The previous prime is 21894813340639. The next prime is 21894813340661. The reversal of 21894813340645 is 54604331849812.

It is a cyclic number.

It is not a de Polignac number, because 21894813340645 - 2⁵ = 21894813340613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21894813340645.

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 31 ways as a sum of consecutive naturals, for example, 163779727 + ... + 163913356.

It is an arithmetic number, because the mean of its divisors is an integer number (990943886016).

Almost surely, 2^{21894813340645} is an apocalyptic number.

It is an amenable number.

21894813340645 is a deficient number, since it is larger than the sum of its proper divisors (9815391011867).

21894813340645 is a wasteful number, since it uses less digits than its factorization.

21894813340645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327693201.

The product of its (nonzero) digits is 19906560, while the sum is 58.

The spelling of 21894813340645 in words is "twenty-one trillion, eight hundred ninety-four billion, eight hundred thirteen million, three hundred forty thousand, six hundred forty-five".