21031005067123 has 2 divisors, whose sum is σ = 21031005067124. Its totient is φ = 21031005067122.

The previous prime is 21031005067117. The next prime is 21031005067147. The reversal of 21031005067123 is 32176050013012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21031005067123 is a prime.

It is not a weakly prime, because it can be changed into another prime (21031005067183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515502533561 + 10515502533562.

It is an arithmetic number, because the mean of its divisors is an integer number (10515502533562).

Almost surely, 2^{21031005067123} is an apocalyptic number.

21031005067123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031005067123 is an equidigital number, since it uses as much as digits as its factorization.

21031005067123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 31.

The spelling of 21031005067123 in words is "twenty-one trillion, thirty-one billion, five million, sixty-seven thousand, one hundred twenty-three".