21020111423 has 8 divisors (see below), whose sum is σ = 21127741440. Its totient is φ = 20912645880.

The previous prime is 21020111419. The next prime is 21020111461. The reversal of 21020111423 is 32411102012.

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

It is a cyclic number.

It is not a de Polignac number, because 21020111423 - 2² = 21020111419 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 (21020111923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 219338 + ... + 300248.

It is an arithmetic number, because the mean of its divisors is an integer number (2640967680).

Almost surely, 2^21020111423 is an apocalyptic number.

21020111423 is a deficient number, since it is larger than the sum of its proper divisors (107630017).

21020111423 is a wasteful number, since it uses less digits than its factorization.

21020111423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82237.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21020111423 its reverse (32411102012), we get a palindrome (53431213435).

The spelling of 21020111423 in words is "twenty-one billion, twenty million, one hundred eleven thousand, four hundred twenty-three".