21523430053 has 2 divisors, whose sum is σ = 21523430054. Its totient is φ = 21523430052.

The previous prime is 21523429981. The next prime is 21523430063. The reversal of 21523430053 is 35003432512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19550471329 + 1972958724 = 139823^2 + 44418^2 .

It is a cyclic number.

It is not a de Polignac number, because 21523430053 - 2⁹ = 21523429541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21523430063) 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, 10761715026 + 10761715027.

It is an arithmetic number, because the mean of its divisors is an integer number (10761715027).

Almost surely, 2^21523430053 is an apocalyptic number.

It is an amenable number.

21523430053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21523430053 is an equidigital number, since it uses as much as digits as its factorization.

21523430053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 28.

Adding to 21523430053 its reverse (35003432512), we get a palindrome (56526862565).

The spelling of 21523430053 in words is "twenty-one billion, five hundred twenty-three million, four hundred thirty thousand, fifty-three".