161623 has 8 divisors (see below), whose sum is σ = 201600. Its totient is φ = 125880.

The previous prime is 161611. The next prime is 161627. The reversal of 161623 is 326161.

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 161623 - 2⁵ = 161591 is a prime.

It is a super-2 number, since 2×161623² = 52243988258, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161627) 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, 973 + ... + 1126.

It is an arithmetic number, because the mean of its divisors is an integer number (25200).

2¹⁶¹⁶²³ is an apocalyptic number.

161623 is a deficient number, since it is larger than the sum of its proper divisors (39977).

161623 is a wasteful number, since it uses less digits than its factorization.

161623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2117.

The product of its digits is 216, while the sum is 19.

The square root of 161623 is about 402.0236311462. The cubic root of 161623 is about 54.4712976268.

Subtracting from 161623 its sum of digits (19), we obtain a square (161604 = 402²).

Adding to 161623 its reverse (326161), we get a palindrome (487784).

It can be divided in two parts, 161 and 623, that added together give a square (784 = 28²).

The spelling of 161623 in words is "one hundred sixty-one thousand, six hundred twenty-three".