161606506566139 has 2 divisors, whose sum is σ = 161606506566140. Its totient is φ = 161606506566138.

The previous prime is 161606506566083. The next prime is 161606506566151. The reversal of 161606506566139 is 931665605606161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161606506566139 - 2¹⁷ = 161606506435067 is a prime.

It is a super-2 number, since 2×161606506566139² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161606506566179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80803253283069 + 80803253283070.

It is an arithmetic number, because the mean of its divisors is an integer number (80803253283070).

Almost surely, 2^{161606506566139} is an apocalyptic number.

161606506566139 is a deficient number, since it is larger than the sum of its proper divisors (1).

161606506566139 is an equidigital number, since it uses as much as digits as its factorization.

161606506566139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31492800, while the sum is 61.

The spelling of 161606506566139 in words is "one hundred sixty-one trillion, six hundred six billion, five hundred six million, five hundred sixty-six thousand, one hundred thirty-nine".