123455531 has 2 divisors, whose sum is σ = 123455532. Its totient is φ = 123455530.

The previous prime is 123455461. The next prime is 123455533. The reversal of 123455531 is 135554321.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123455531 is a prime.

It is a super-2 number, since 2×123455531² = 30482536268983922, which contains 22 as substring.

Together with 123455533, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 123455494 and 123455503.

It is not a weakly prime, because it can be changed into another prime (123455533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61727765 + 61727766.

It is an arithmetic number, because the mean of its divisors is an integer number (61727766).

Almost surely, 2^123455531 is an apocalyptic number.

123455531 is a deficient number, since it is larger than the sum of its proper divisors (1).

123455531 is an equidigital number, since it uses as much as digits as its factorization.

123455531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9000, while the sum is 29.

The square root of 123455531 is about 11111.0544504111. The cubic root of 123455531 is about 497.9321679303.

It can be divided in two parts, 1234 and 55531, that added together give a palindrome (56765).

The spelling of 123455531 in words is "one hundred twenty-three million, four hundred fifty-five thousand, five hundred thirty-one".