161608168906 has 4 divisors (see below), whose sum is σ = 242412253362. Its totient is φ = 80804084452.

The previous prime is 161608168901. The next prime is 161608168951. The reversal of 161608168906 is 609861806161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 609861806161 = 4721 ⋅129180641.

It can be written as a sum of positive squares in only one way, i.e., 150575817681 + 11032351225 = 388041^2 + 105035^2 .

It is a super-2 number, since 2×161608168906² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161608168901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40402042225 + ... + 40402042228.

Almost surely, 2^161608168906 is an apocalyptic number.

161608168906 is a deficient number, since it is larger than the sum of its proper divisors (80804084456).

161608168906 is an equidigital number, since it uses as much as digits as its factorization.

161608168906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80804084455.

The product of its (nonzero) digits is 746496, while the sum is 52.

The spelling of 161608168906 in words is "one hundred sixty-one billion, six hundred eight million, one hundred sixty-eight thousand, nine hundred six".