123208722121 has 3 divisors (see below), whose sum is σ = 123209073133. Its totient is φ = 123208371110.

The previous prime is 123208722107. The next prime is 123208722139. The reversal of 123208722121 is 121227802321.

The square root of 123208722121 is 351011.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 123208722121 - 2⁵ = 123208722089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123208725121) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 175506 + ... + 526516.

Almost surely, 2^123208722121 is an apocalyptic number.

123208722121 is the 351011-st square number.

123208722121 is the 175506-th centered octagonal number.

It is an amenable number.

123208722121 is a deficient number, since it is larger than the sum of its proper divisors (351012).

123208722121 is an frugal number, since it uses more digits than its factorization.

123208722121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 702022 (or 351011 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The spelling of 123208722121 in words is "one hundred twenty-three billion, two hundred eight million, seven hundred twenty-two thousand, one hundred twenty-one".