123291281 has 4 divisors (see below), whose sum is σ = 123382452. Its totient is φ = 123200112.

The previous prime is 123291241. The next prime is 123291283. The reversal of 123291281 is 182192321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 182192321 = 739 ⋅246539.

It can be written as a sum of positive squares in 2 ways, for example, as 82446400 + 40844881 = 9080^2 + 6391^2 .

It is a cyclic number.

It is not a de Polignac number, because 123291281 - 2¹⁴ = 123274897 is a prime.

It is a super-2 number, since 2×123291281² = 30401479941241922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123291283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43526 + ... + 46271.

It is an arithmetic number, because the mean of its divisors is an integer number (30845613).

Almost surely, 2^123291281 is an apocalyptic number.

It is an amenable number.

123291281 is a deficient number, since it is larger than the sum of its proper divisors (91171).

123291281 is an equidigital number, since it uses as much as digits as its factorization.

123291281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91170.

The product of its digits is 1728, while the sum is 29.

The square root of 123291281 is about 11103.6607026692. The cubic root of 123291281 is about 497.7112472071.

The spelling of 123291281 in words is "one hundred twenty-three million, two hundred ninety-one thousand, two hundred eighty-one".