21110230021 has 4 divisors (see below), whose sum is σ = 21236638752. Its totient is φ = 20983821292.

The previous prime is 21110230007. The next prime is 21110230027. The reversal of 21110230021 is 12003201112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21110230021 - 2²⁹ = 20573359109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110229983 and 21110230010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110230027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63204115 + ... + 63204448.

It is an arithmetic number, because the mean of its divisors is an integer number (5309159688).

Almost surely, 2^21110230021 is an apocalyptic number.

It is an amenable number.

21110230021 is a deficient number, since it is larger than the sum of its proper divisors (126408731).

21110230021 is a wasteful number, since it uses less digits than its factorization.

21110230021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126408730.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21110230021 its reverse (12003201112), we get a palindrome (33113431133).

The spelling of 21110230021 in words is "twenty-one billion, one hundred ten million, two hundred thirty thousand, twenty-one".