21203200123 has 4 divisors (see below), whose sum is σ = 24232228720. Its totient is φ = 18174171528.

The previous prime is 21203200121. The next prime is 21203200133. The reversal of 21203200123 is 32100230212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21203200123 - 2¹ = 21203200121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21203200097 and 21203200106.

It is not an unprimeable number, because it can be changed into a prime (21203200121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1514514288 + ... + 1514514301.

It is an arithmetic number, because the mean of its divisors is an integer number (6058057180).

Almost surely, 2^21203200123 is an apocalyptic number.

21203200123 is a deficient number, since it is larger than the sum of its proper divisors (3029028597).

21203200123 is an equidigital number, since it uses as much as digits as its factorization.

21203200123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3029028596.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21203200123 its reverse (32100230212), we get a palindrome (53303430335).

The spelling of 21203200123 in words is "twenty-one billion, two hundred three million, two hundred thousand, one hundred twenty-three".