161261945 has 32 divisors (see below), whose sum is σ = 214389504. Its totient is φ = 115718400.

The previous prime is 161261941. The next prime is 161261951. The reversal of 161261945 is 549162161.

It is not a de Polignac number, because 161261945 - 2² = 161261941 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161261941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 382835 + ... + 383255.

It is an arithmetic number, because the mean of its divisors is an integer number (6699672).

Almost surely, 2^161261945 is an apocalyptic number.

It is an amenable number.

161261945 is a deficient number, since it is larger than the sum of its proper divisors (53127559).

161261945 is a wasteful number, since it uses less digits than its factorization.

161261945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 593.

The product of its digits is 12960, while the sum is 35.

The square root of 161261945 is about 12698.8954244060. The cubic root of 161261945 is about 544.3070563683.

The spelling of 161261945 in words is "one hundred sixty-one million, two hundred sixty-one thousand, nine hundred forty-five".