21200320123 has 2 divisors, whose sum is σ = 21200320124. Its totient is φ = 21200320122.

The previous prime is 21200320117. The next prime is 21200320129. The reversal of 21200320123 is 32102300212.

It is a balanced prime because it is at equal distance from previous prime (21200320117) and next prime (21200320129).

It is a cyclic number.

It is not a de Polignac number, because 21200320123 - 2⁹ = 21200319611 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200320097 and 21200320106.

It is not a weakly prime, because it can be changed into another prime (21200320129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600160061 + 10600160062.

It is an arithmetic number, because the mean of its divisors is an integer number (10600160062).

Almost surely, 2^21200320123 is an apocalyptic number.

21200320123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200320123 is an equidigital number, since it uses as much as digits as its factorization.

21200320123 is an evil number, because the sum of its binary digits is even.

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

Adding to 21200320123 its reverse (32102300212), we get a palindrome (53302620335).

The spelling of 21200320123 in words is "twenty-one billion, two hundred million, three hundred twenty thousand, one hundred twenty-three".