161603381 has 8 divisors (see below), whose sum is σ = 163081728. Its totient is φ = 160132000.

The previous prime is 161603357. The next prime is 161603389. The reversal of 161603381 is 183306161.

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

It is a cyclic number.

It is not a de Polignac number, because 161603381 - 2⁶ = 161603317 is a prime.

It is a super-3 number, since 3×161603381³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161603389) 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, 52166 + ... + 55176.

It is an arithmetic number, because the mean of its divisors is an integer number (20385216).

Almost surely, 2^161603381 is an apocalyptic number.

It is an amenable number.

161603381 is a deficient number, since it is larger than the sum of its proper divisors (1478347).

161603381 is a wasteful number, since it uses less digits than its factorization.

161603381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3483.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 161603381 is about 12712.3318474621. The cubic root of 161603381 is about 544.6909349408.

The spelling of 161603381 in words is "one hundred sixty-one million, six hundred three thousand, three hundred eighty-one".