161265603 has 4 divisors (see below), whose sum is σ = 215020808. Its totient is φ = 107510400.

The previous prime is 161265563. The next prime is 161265613. The reversal of 161265603 is 306562161.

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

It is not a de Polignac number, because 161265603 - 2⁸ = 161265347 is a prime.

It is a super-3 number, since 3×161265603³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161265613) 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, 26877598 + ... + 26877603.

It is an arithmetic number, because the mean of its divisors is an integer number (53755202).

Almost surely, 2^161265603 is an apocalyptic number.

161265603 is a deficient number, since it is larger than the sum of its proper divisors (53755205).

161265603 is an equidigital number, since it uses as much as digits as its factorization.

161265603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53755204.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 161265603 is about 12699.0394518641. The cubic root of 161265603 is about 544.3111719500.

The spelling of 161265603 in words is "one hundred sixty-one million, two hundred sixty-five thousand, six hundred three".