16245536561 has 2 divisors, whose sum is σ = 16245536562. Its totient is φ = 16245536560.

The previous prime is 16245536539. The next prime is 16245536669. The reversal of 16245536561 is 16563554261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14874241600 + 1371294961 = 121960^2 + 37031^2 .

It is an emirp because it is prime and its reverse (16563554261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16245536561 - 2¹⁴ = 16245520177 is a prime.

It is not a weakly prime, because it can be changed into another prime (16245532561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8122768280 + 8122768281.

It is an arithmetic number, because the mean of its divisors is an integer number (8122768281).

Almost surely, 2^16245536561 is an apocalyptic number.

It is an amenable number.

16245536561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16245536561 is an equidigital number, since it uses as much as digits as its factorization.

16245536561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648000, while the sum is 44.

The spelling of 16245536561 in words is "sixteen billion, two hundred forty-five million, five hundred thirty-six thousand, five hundred sixty-one".