21003023123 has 2 divisors, whose sum is σ = 21003023124. Its totient is φ = 21003023122.

The previous prime is 21003023089. The next prime is 21003023131. The reversal of 21003023123 is 32132030012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21003023123 - 2⁶ = 21003023059 is a prime.

It is a super-2 number, since 2×21003023123² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21003023143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501511561 + 10501511562.

It is an arithmetic number, because the mean of its divisors is an integer number (10501511562).

Almost surely, 2^21003023123 is an apocalyptic number.

21003023123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003023123 is an equidigital number, since it uses as much as digits as its factorization.

21003023123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21003023123 its reverse (32132030012), we get a palindrome (53135053135).

The spelling of 21003023123 in words is "twenty-one billion, three million, twenty-three thousand, one hundred twenty-three".