21800270123 has 2 divisors, whose sum is σ = 21800270124. Its totient is φ = 21800270122.

The previous prime is 21800270117. The next prime is 21800270197. The reversal of 21800270123 is 32107200812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21800270123 - 2²⁰ = 21799221547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21800270092 and 21800270101.

It is not a weakly prime, because it can be changed into another prime (21800270623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10900135061 + 10900135062.

It is an arithmetic number, because the mean of its divisors is an integer number (10900135062).

Almost surely, 2^21800270123 is an apocalyptic number.

21800270123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21800270123 is an equidigital number, since it uses as much as digits as its factorization.

21800270123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

Adding to 21800270123 its reverse (32107200812), we get a palindrome (53907470935).

The spelling of 21800270123 in words is "twenty-one billion, eight hundred million, two hundred seventy thousand, one hundred twenty-three".