161661423 has 32 divisors (see below), whose sum is σ = 269383680. Its totient is φ = 83777760.

The previous prime is 161661421. The next prime is 161661427. The reversal of 161661423 is 324166161.

It is not a de Polignac number, because 161661423 - 2¹ = 161661421 is a prime.

It is a super-2 number, since 2×161661423² = 52268831372769858, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161661421) 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, 170236 + ... + 171182.

It is an arithmetic number, because the mean of its divisors is an integer number (8418240).

Almost surely, 2^161661423 is an apocalyptic number.

161661423 is a deficient number, since it is larger than the sum of its proper divisors (107722257).

161661423 is a wasteful number, since it uses less digits than its factorization.

161661423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1707.

The product of its digits is 5184, while the sum is 30.

The square root of 161661423 is about 12714.6145439018. The cubic root of 161661423 is about 544.7561381290.

The spelling of 161661423 in words is "one hundred sixty-one million, six hundred sixty-one thousand, four hundred twenty-three".