123017921 has 8 divisors (see below), whose sum is σ = 134296680. Its totient is φ = 111998592.

The previous prime is 123017911. The next prime is 123017927. The reversal of 123017921 is 129710321.

It can be written as a sum of positive squares in 4 ways, for example, as 583696 + 122434225 = 764^2 + 11065^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 123017921 - 2⁶ = 123017857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123017927) 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 7 ways as a sum of consecutive naturals, for example, 63866 + ... + 65763.

It is an arithmetic number, because the mean of its divisors is an integer number (16787085).

Almost surely, 2^123017921 is an apocalyptic number.

It is an amenable number.

123017921 is a deficient number, since it is larger than the sum of its proper divisors (11278759).

123017921 is a wasteful number, since it uses less digits than its factorization.

123017921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129715.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 123017921 is about 11091.3444180586. The cubic root of 123017921 is about 497.3431351444.

The spelling of 123017921 in words is "one hundred twenty-three million, seventeen thousand, nine hundred twenty-one".