161515505603 has 2 divisors, whose sum is σ = 161515505604. Its totient is φ = 161515505602.

The previous prime is 161515505537. The next prime is 161515505617. The reversal of 161515505603 is 306505515161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161515505603 - 2¹⁶ = 161515440067 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (161515585603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80757752801 + 80757752802.

It is an arithmetic number, because the mean of its divisors is an integer number (80757752802).

Almost surely, 2^161515505603 is an apocalyptic number.

161515505603 is a deficient number, since it is larger than the sum of its proper divisors (1).

161515505603 is an equidigital number, since it uses as much as digits as its factorization.

161515505603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 67500, while the sum is 38.

The spelling of 161515505603 in words is "one hundred sixty-one billion, five hundred fifteen million, five hundred five thousand, six hundred three".