123423561 has 16 divisors (see below), whose sum is σ = 184629120. Its totient is φ = 81481680.

The previous prime is 123423541. The next prime is 123423569. The reversal of 123423561 is 165324321.

It is not a de Polignac number, because 123423561 - 2⁵ = 123423529 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (123423569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19410 + ... + 24971.

It is an arithmetic number, because the mean of its divisors is an integer number (11539320).

Almost surely, 2^123423561 is an apocalyptic number.

It is an amenable number.

123423561 is a deficient number, since it is larger than the sum of its proper divisors (61205559).

123423561 is a wasteful number, since it uses less digits than its factorization.

123423561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44493 (or 44487 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 123423561 is about 11109.6156999241. The cubic root of 123423561 is about 497.8891827744.

Adding to 123423561 its reverse (165324321), we get a palindrome (288747882).

The spelling of 123423561 in words is "one hundred twenty-three million, four hundred twenty-three thousand, five hundred sixty-one".