12423522721 has 4 divisors (see below), whose sum is σ = 12429745812. Its totient is φ = 12417299632.

The previous prime is 12423522677. The next prime is 12423522731. The reversal of 12423522721 is 12722532421.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1708995600 + 10714527121 = 41340^2 + 103511^2 .

It is a cyclic number.

It is not a de Polignac number, because 12423522721 - 2¹³ = 12423514529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12423522731) 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, 3108550 + ... + 3112543.

It is an arithmetic number, because the mean of its divisors is an integer number (3107436453).

Almost surely, 2^12423522721 is an apocalyptic number.

It is an amenable number.

12423522721 is a deficient number, since it is larger than the sum of its proper divisors (6223091).

12423522721 is an equidigital number, since it uses as much as digits as its factorization.

12423522721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6223090.

The product of its digits is 13440, while the sum is 31.

The spelling of 12423522721 in words is "twelve billion, four hundred twenty-three million, five hundred twenty-two thousand, seven hundred twenty-one".