123012921 has 4 divisors (see below), whose sum is σ = 164017232. Its totient is φ = 82008612.

The previous prime is 123012913. The next prime is 123012943. The reversal of 123012921 is 129210321.

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 not a de Polignac number, because 123012921 - 2³ = 123012913 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 (123012961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20502151 + ... + 20502156.

It is an arithmetic number, because the mean of its divisors is an integer number (41004308).

Almost surely, 2^123012921 is an apocalyptic number.

It is an amenable number.

123012921 is a deficient number, since it is larger than the sum of its proper divisors (41004311).

123012921 is an equidigital number, since it uses as much as digits as its factorization.

123012921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41004310.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 123012921 is about 11091.1190147793. The cubic root of 123012921 is about 497.3363969680.

The spelling of 123012921 in words is "one hundred twenty-three million, twelve thousand, nine hundred twenty-one".