123454721 has 4 divisors (see below), whose sum is σ = 132951252. Its totient is φ = 113958192.

The previous prime is 123454691. The next prime is 123454883. The reversal of 123454721 is 127454321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127454321 = 17 ⋅7497313.

It can be written as a sum of positive squares in 2 ways, for example, as 18105025 + 105349696 = 4255^2 + 10264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123454721 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123454921) 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, 4748246 + ... + 4748271.

It is an arithmetic number, because the mean of its divisors is an integer number (33237813).

Almost surely, 2^123454721 is an apocalyptic number.

It is an amenable number.

123454721 is a deficient number, since it is larger than the sum of its proper divisors (9496531).

123454721 is an equidigital number, since it uses as much as digits as its factorization.

123454721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9496530.

The product of its digits is 6720, while the sum is 29.

The square root of 123454721 is about 11111.0180001654. The cubic root of 123454721 is about 497.9310789391.

It can be divided in two parts, 1234 and 54721, that added together give a palindrome (55955).

The spelling of 123454721 in words is "one hundred twenty-three million, four hundred fifty-four thousand, seven hundred twenty-one".