123288821 has 4 divisors (see below), whose sum is σ = 123534432. Its totient is φ = 123043212.

The previous prime is 123288817. The next prime is 123288859. The reversal of 123288821 is 128882321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 128882321 = 17 ⋅7581313.

It is a cyclic number.

It is not a de Polignac number, because 123288821 - 2² = 123288817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123288871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122051 + ... + 123056.

It is an arithmetic number, because the mean of its divisors is an integer number (30883608).

Almost surely, 2^123288821 is an apocalyptic number.

It is an amenable number.

123288821 is a deficient number, since it is larger than the sum of its proper divisors (245611).

123288821 is an equidigital number, since it uses as much as digits as its factorization.

123288821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245610.

The product of its digits is 12288, while the sum is 35.

The square root of 123288821 is about 11103.5499278384. The cubic root of 123288821 is about 497.7079369492.

The spelling of 123288821 in words is "one hundred twenty-three million, two hundred eighty-eight thousand, eight hundred twenty-one".