161605999999979 has 2 divisors, whose sum is σ = 161605999999980. Its totient is φ = 161605999999978.

The previous prime is 161605999999933. The next prime is 161605999999987. The reversal of 161605999999979 is 979999999506161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161605999999979 - 2¹² = 161605999995883 is a prime.

It is a super-2 number, since 2×161605999999979² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161605999999079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80802999999989 + 80802999999990.

It is an arithmetic number, because the mean of its divisors is an integer number (80802999999990).

Almost surely, 2^{161605999999979} is an apocalyptic number.

161605999999979 is a deficient number, since it is larger than the sum of its proper divisors (1).

161605999999979 is an equidigital number, since it uses as much as digits as its factorization.

161605999999979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54238868460, while the sum is 98.

The spelling of 161605999999979 in words is "one hundred sixty-one trillion, six hundred five billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventy-nine".