161187261 has 8 divisors (see below), whose sum is σ = 216925344. Its totient is φ = 106453680.

The previous prime is 161187227. The next prime is 161187283. The reversal of 161187261 is 162781161.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161187261 - 2¹³ = 161179069 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161187361) 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, 250750 + ... + 251391.

It is an arithmetic number, because the mean of its divisors is an integer number (27115668).

Almost surely, 2^161187261 is an apocalyptic number.

It is an amenable number.

161187261 is a deficient number, since it is larger than the sum of its proper divisors (55738083).

161187261 is a wasteful number, since it uses less digits than its factorization.

161187261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502251.

The product of its digits is 4032, while the sum is 33.

The square root of 161187261 is about 12695.9545131510. The cubic root of 161187261 is about 544.2230164846.

The spelling of 161187261 in words is "one hundred sixty-one million, one hundred eighty-seven thousand, two hundred sixty-one".