1561720516099 has 2 divisors, whose sum is σ = 1561720516100. Its totient is φ = 1561720516098.

The previous prime is 1561720516093. The next prime is 1561720516117. The reversal of 1561720516099 is 9906150271651.

It is a weak prime.

It is an emirp because it is prime and its reverse (9906150271651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1561720516099 - 2⁹ = 1561720515587 is a prime.

It is not a weakly prime, because it can be changed into another prime (1561720516093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780860258049 + 780860258050.

It is an arithmetic number, because the mean of its divisors is an integer number (780860258050).

Almost surely, 2^{1561720516099} is an apocalyptic number.

1561720516099 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561720516099 is an equidigital number, since it uses as much as digits as its factorization.

1561720516099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1020600, while the sum is 52.

The spelling of 1561720516099 in words is "one trillion, five hundred sixty-one billion, seven hundred twenty million, five hundred sixteen thousand, ninety-nine".