21879046645 has 32 divisors (see below), whose sum is σ = 27543662208. Its totient is φ = 16667659008.

The previous prime is 21879046643. The next prime is 21879046681. The reversal of 21879046645 is 54664097812.

It is a cyclic number.

It is not a de Polignac number, because 21879046645 - 2¹ = 21879046643 is a prime.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21879046592 and 21879046601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21879046643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1940394 + ... + 1951636.

It is an arithmetic number, because the mean of its divisors is an integer number (860739444).

Almost surely, 2^21879046645 is an apocalyptic number.

It is an amenable number.

21879046645 is a deficient number, since it is larger than the sum of its proper divisors (5664615563).

21879046645 is a wasteful number, since it uses less digits than its factorization.

21879046645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11509.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 21879046645 in words is "twenty-one billion, eight hundred seventy-nine million, forty-six thousand, six hundred forty-five".