21351124523 has 2 divisors, whose sum is σ = 21351124524. Its totient is φ = 21351124522.

The previous prime is 21351124499. The next prime is 21351124603. The reversal of 21351124523 is 32542115312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21351124523 - 2¹⁰ = 21351123499 is a prime.

It is not a weakly prime, because it can be changed into another prime (21351124723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10675562261 + 10675562262.

It is an arithmetic number, because the mean of its divisors is an integer number (10675562262).

Almost surely, 2^21351124523 is an apocalyptic number.

21351124523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21351124523 is an equidigital number, since it uses as much as digits as its factorization.

21351124523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 29.

Adding to 21351124523 its reverse (32542115312), we get a palindrome (53893239835).

The spelling of 21351124523 in words is "twenty-one billion, three hundred fifty-one million, one hundred twenty-four thousand, five hundred twenty-three".