21879046643 has 2 divisors, whose sum is σ = 21879046644. Its totient is φ = 21879046642.

The previous prime is 21879046639. The next prime is 21879046681. The reversal of 21879046643 is 34664097812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21879046643 - 2² = 21879046639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21879046591 and 21879046600.

It is not a weakly prime, because it can be changed into another prime (21879046043) 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 as a sum of consecutive naturals, namely, 10939523321 + 10939523322.

It is an arithmetic number, because the mean of its divisors is an integer number (10939523322).

Almost surely, 2^21879046643 is an apocalyptic number.

21879046643 is a deficient number, since it is larger than the sum of its proper divisors (1).

21879046643 is an equidigital number, since it uses as much as digits as its factorization.

21879046643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1741824, while the sum is 50.

The spelling of 21879046643 in words is "twenty-one billion, eight hundred seventy-nine million, forty-six thousand, six hundred forty-three".