123289921 has 4 divisors (see below), whose sum is σ = 124028352. Its totient is φ = 122551492.

The previous prime is 123289909. The next prime is 123289937. The reversal of 123289921 is 129982321.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123289921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123289951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 368965 + ... + 369298.

It is an arithmetic number, because the mean of its divisors is an integer number (31007088).

Almost surely, 2^123289921 is an apocalyptic number.

It is an amenable number.

123289921 is a deficient number, since it is larger than the sum of its proper divisors (738431).

123289921 is an equidigital number, since it uses as much as digits as its factorization.

123289921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738430.

The product of its digits is 15552, while the sum is 37.

The square root of 123289921 is about 11103.5994614359. The cubic root of 123289921 is about 497.7094171513.

The spelling of 123289921 in words is "one hundred twenty-three million, two hundred eighty-nine thousand, nine hundred twenty-one".