161271906 has 16 divisors (see below), whose sum is σ = 336567744. Its totient is φ = 51419984.

The previous prime is 161271841. The next prime is 161271907. The reversal of 161271906 is 609172161.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161271907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 584181 + ... + 584456.

It is an arithmetic number, because the mean of its divisors is an integer number (21035484).

Almost surely, 2^161271906 is an apocalyptic number.

161271906 is an abundant number, since it is smaller than the sum of its proper divisors (175295838).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161271906 is a wasteful number, since it uses less digits than its factorization.

161271906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1168665.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 161271906 is about 12699.2876178154. The cubic root of 161271906 is about 544.3182632507.

The spelling of 161271906 in words is "one hundred sixty-one million, two hundred seventy-one thousand, nine hundred six".