161601665667 has 32 divisors (see below), whose sum is σ = 239570989056. Its totient is φ = 96222211200.

The previous prime is 161601665663. The next prime is 161601665669. The reversal of 161601665667 is 766566106161.

It is a happy number.

It is not a de Polignac number, because 161601665667 - 2² = 161601665663 is a prime.

It is a super-2 number, since 2×161601665667² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161601665663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11394993 + ... + 11409165.

It is an arithmetic number, because the mean of its divisors is an integer number (7486593408).

Almost surely, 2^161601665667 is an apocalyptic number.

161601665667 is a deficient number, since it is larger than the sum of its proper divisors (77969323389).

161601665667 is a wasteful number, since it uses less digits than its factorization.

161601665667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23651.

The product of its (nonzero) digits is 1632960, while the sum is 51.

The spelling of 161601665667 in words is "one hundred sixty-one billion, six hundred one million, six hundred sixty-five thousand, six hundred sixty-seven".