123305531 has 4 divisors (see below), whose sum is σ = 123345600. Its totient is φ = 123265464.

The previous prime is 123305521. The next prime is 123305537. The reversal of 123305531 is 135503321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 123305531 - 2¹⁸ = 123043387 is a prime.

It is a super-2 number, since 2×123305531² = 30408507950383922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123305497 and 123305506.

It is not an unprimeable number, because it can be changed into a prime (123305537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14996 + ... + 21713.

It is an arithmetic number, because the mean of its divisors is an integer number (30836400).

Almost surely, 2^123305531 is an apocalyptic number.

123305531 is a deficient number, since it is larger than the sum of its proper divisors (40069).

123305531 is an equidigital number, since it uses as much as digits as its factorization.

123305531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40068.

The product of its (nonzero) digits is 1350, while the sum is 23.

The square root of 123305531 is about 11104.3023643991. The cubic root of 123305531 is about 497.7304216153.

Adding to 123305531 its reverse (135503321), we get a palindrome (258808852).

The spelling of 123305531 in words is "one hundred twenty-three million, three hundred five thousand, five hundred thirty-one".