16521964243 has 2 divisors, whose sum is σ = 16521964244. Its totient is φ = 16521964242.

The previous prime is 16521964213. The next prime is 16521964307. The reversal of 16521964243 is 34246912561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16521964243 - 2²⁹ = 15985093331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16521964243.

It is not a weakly prime, because it can be changed into another prime (16521964213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8260982121 + 8260982122.

It is an arithmetic number, because the mean of its divisors is an integer number (8260982122).

Almost surely, 2^16521964243 is an apocalyptic number.

16521964243 is a deficient number, since it is larger than the sum of its proper divisors (1).

16521964243 is an equidigital number, since it uses as much as digits as its factorization.

16521964243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 43.

The spelling of 16521964243 in words is "sixteen billion, five hundred twenty-one million, nine hundred sixty-four thousand, two hundred forty-three".