161606381794809 has 32 divisors (see below), whose sum is σ = 246520865525760. Its totient is φ = 92247725361792.

The previous prime is 161606381794807. The next prime is 161606381794813. The reversal of 161606381794809 is 908497183606161.

It is not a de Polignac number, because 161606381794809 - 2¹ = 161606381794807 is a prime.

It is a super-2 number, since 2×161606381794809² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161606381794807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 91347922 + ... + 93100244.

It is an arithmetic number, because the mean of its divisors is an integer number (7703777047680).

Almost surely, 2^{161606381794809} is an apocalyptic number.

It is an amenable number.

161606381794809 is a deficient number, since it is larger than the sum of its proper divisors (84914483730951).

161606381794809 is a wasteful number, since it uses less digits than its factorization.

161606381794809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757029.

The product of its (nonzero) digits is 94058496, while the sum is 69.

The spelling of 161606381794809 in words is "one hundred sixty-one trillion, six hundred six billion, three hundred eighty-one million, seven hundred ninety-four thousand, eight hundred nine".