161603405 has 8 divisors (see below), whose sum is σ = 202355712. Its totient is φ = 123661648.

The previous prime is 161603389. The next prime is 161603443. The reversal of 161603405 is 504306161.

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 161603405 - 2⁴ = 161603389 is a prime.

It is a super-2 number, since 2×161603405² = 52231321015188050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 702509 + ... + 702738.

It is an arithmetic number, because the mean of its divisors is an integer number (25294464).

Almost surely, 2^161603405 is an apocalyptic number.

It is an amenable number.

161603405 is a deficient number, since it is larger than the sum of its proper divisors (40752307).

161603405 is a wasteful number, since it uses less digits than its factorization.

161603405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1405275.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 161603405 is about 12712.3327914274. The cubic root of 161603405 is about 544.6909619051.

Adding to 161603405 its reverse (504306161), we get a palindrome (665909566).

The spelling of 161603405 in words is "one hundred sixty-one million, six hundred three thousand, four hundred five".