21885018943 has 4 divisors (see below), whose sum is σ = 22590987328. Its totient is φ = 21179050560.

The previous prime is 21885018937. The next prime is 21885018971. The reversal of 21885018943 is 34981058812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21885018943 - 2¹³ = 21885010751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21885018973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 352984146 + ... + 352984207.

It is an arithmetic number, because the mean of its divisors is an integer number (5647746832).

Almost surely, 2^21885018943 is an apocalyptic number.

21885018943 is a deficient number, since it is larger than the sum of its proper divisors (705968385).

21885018943 is an equidigital number, since it uses as much as digits as its factorization.

21885018943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705968384.

The product of its (nonzero) digits is 552960, while the sum is 49.

The spelling of 21885018943 in words is "twenty-one billion, eight hundred eighty-five million, eighteen thousand, nine hundred forty-three".