16421523553 has 2 divisors, whose sum is σ = 16421523554. Its totient is φ = 16421523552.

The previous prime is 16421523527. The next prime is 16421523563. The reversal of 16421523553 is 35532512461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12278412864 + 4143110689 = 110808^2 + 64367^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16421523553 is a prime.

It is not a weakly prime, because it can be changed into another prime (16421523563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8210761776 + 8210761777.

It is an arithmetic number, because the mean of its divisors is an integer number (8210761777).

Almost surely, 2^16421523553 is an apocalyptic number.

It is an amenable number.

16421523553 is a deficient number, since it is larger than the sum of its proper divisors (1).

16421523553 is an equidigital number, since it uses as much as digits as its factorization.

16421523553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108000, while the sum is 37.

The spelling of 16421523553 in words is "sixteen billion, four hundred twenty-one million, five hundred twenty-three thousand, five hundred fifty-three".