21105104023 has 2 divisors, whose sum is σ = 21105104024. Its totient is φ = 21105104022.

The previous prime is 21105103997. The next prime is 21105104047. The reversal of 21105104023 is 32040150112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21105104023 - 2¹³ = 21105095831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21105164023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10552552011 + 10552552012.

It is an arithmetic number, because the mean of its divisors is an integer number (10552552012).

Almost surely, 2^21105104023 is an apocalyptic number.

21105104023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21105104023 is an equidigital number, since it uses as much as digits as its factorization.

21105104023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21105104023 its reverse (32040150112), we get a palindrome (53145254135).

The spelling of 21105104023 in words is "twenty-one billion, one hundred five million, one hundred four thousand, twenty-three".