21418125823 has 2 divisors, whose sum is σ = 21418125824. Its totient is φ = 21418125822.

The previous prime is 21418125809. The next prime is 21418125851. The reversal of 21418125823 is 32852181412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21418125823 - 2⁵ = 21418125791 is a prime.

It is a super-2 number, since 2×21418125823² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21418125853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10709062911 + 10709062912.

It is an arithmetic number, because the mean of its divisors is an integer number (10709062912).

Almost surely, 2^21418125823 is an apocalyptic number.

21418125823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21418125823 is an equidigital number, since it uses as much as digits as its factorization.

21418125823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30720, while the sum is 37.

The spelling of 21418125823 in words is "twenty-one billion, four hundred eighteen million, one hundred twenty-five thousand, eight hundred twenty-three".