21023218994 has 8 divisors (see below), whose sum is σ = 32622236460. Its totient is φ = 10149140176.

The previous prime is 21023218991. The next prime is 21023219089. The reversal of 21023218994 is 49981232012.

21023218994 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 20040082969 + 983136025 = 141563^2 + 31355^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21023218991) 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 3 ways as a sum of consecutive naturals, for example, 181234589 + ... + 181234704.

Almost surely, 2^21023218994 is an apocalyptic number.

21023218994 is a deficient number, since it is larger than the sum of its proper divisors (11599017466).

21023218994 is a wasteful number, since it uses less digits than its factorization.

21023218994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362469324.

The product of its (nonzero) digits is 62208, while the sum is 41.

The spelling of 21023218994 in words is "twenty-one billion, twenty-three million, two hundred eighteen thousand, nine hundred ninety-four".