161872011 has 24 divisors (see below), whose sum is σ = 282937824. Its totient is φ = 87056640.

The previous prime is 161871989. The next prime is 161872057. The reversal of 161872011 is 110278161.

It is not a de Polignac number, because 161872011 - 2⁶ = 161871947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161872211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74500 + ... + 76641.

It is an arithmetic number, because the mean of its divisors is an integer number (11789076).

Almost surely, 2^161872011 is an apocalyptic number.

161872011 is a deficient number, since it is larger than the sum of its proper divisors (121065813).

161872011 is a wasteful number, since it uses less digits than its factorization.

161872011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151171 (or 151168 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 27.

The square root of 161872011 is about 12722.8931851211. The cubic root of 161872011 is about 544.9925774036.

The spelling of 161872011 in words is "one hundred sixty-one million, eight hundred seventy-two thousand, eleven".