21534535123 has 2 divisors, whose sum is σ = 21534535124. Its totient is φ = 21534535122.

The previous prime is 21534535073. The next prime is 21534535159. The reversal of 21534535123 is 32153543512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21534535123 is a prime.

It is not a weakly prime, because it can be changed into another prime (21534505123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767267561 + 10767267562.

It is an arithmetic number, because the mean of its divisors is an integer number (10767267562).

Almost surely, 2^21534535123 is an apocalyptic number.

21534535123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534535123 is an equidigital number, since it uses as much as digits as its factorization.

21534535123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54000, while the sum is 34.

The spelling of 21534535123 in words is "twenty-one billion, five hundred thirty-four million, five hundred thirty-five thousand, one hundred twenty-three".