123120021 has 8 divisors (see below), whose sum is σ = 166851424. Its totient is φ = 80734320.

The previous prime is 123120017. The next prime is 123120029. The reversal of 123120021 is 120021321.

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

It is not a de Polignac number, because 123120021 - 2² = 123120017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123119979 and 123120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123120029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336211 + ... + 336576.

It is an arithmetic number, because the mean of its divisors is an integer number (20856428).

Almost surely, 2^123120021 is an apocalyptic number.

It is an amenable number.

123120021 is a deficient number, since it is larger than the sum of its proper divisors (43731403).

123120021 is an equidigital number, since it uses as much as digits as its factorization.

123120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672851.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 123120021 is about 11095.9461516357. The cubic root of 123120021 is about 497.4806887953.

Adding to 123120021 its reverse (120021321), we get a palindrome (243141342).

The spelling of 123120021 in words is "one hundred twenty-three million, one hundred twenty thousand, twenty-one".