161540045 has 4 divisors (see below), whose sum is σ = 193848060. Its totient is φ = 129232032.

The previous prime is 161539997. The next prime is 161540047. The reversal of 161540045 is 540045161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39702601 + 121837444 = 6301^2 + 11038^2 .

It is a cyclic number.

It is not a de Polignac number, because 161540045 - 2⁸ = 161539789 is a prime.

It is a super-2 number, since 2×161540045² = 52190372277204050, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 161539996 and 161540023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161540047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16154000 + ... + 16154009.

It is an arithmetic number, because the mean of its divisors is an integer number (48462015).

Almost surely, 2^161540045 is an apocalyptic number.

It is an amenable number.

161540045 is a deficient number, since it is larger than the sum of its proper divisors (32308015).

161540045 is an equidigital number, since it uses as much as digits as its factorization.

161540045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32308014.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 161540045 is about 12709.8404789360. The cubic root of 161540045 is about 544.6197667661.

The spelling of 161540045 in words is "one hundred sixty-one million, five hundred forty thousand, forty-five".