123664421 has 4 divisors (see below), whose sum is σ = 123713100. Its totient is φ = 123615744.

The previous prime is 123664403. The next prime is 123664433. The reversal of 123664421 is 124466321.

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 2356225 + 121308196 = 1535^2 + 11014^2 .

It is a cyclic number.

It is not a de Polignac number, because 123664421 - 2¹⁸ = 123402277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123664451) 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, 20306 + ... + 25683.

It is an arithmetic number, because the mean of its divisors is an integer number (30928275).

Almost surely, 2^123664421 is an apocalyptic number.

It is an amenable number.

123664421 is a deficient number, since it is larger than the sum of its proper divisors (48679).

123664421 is an equidigital number, since it uses as much as digits as its factorization.

123664421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48678.

The product of its digits is 6912, while the sum is 29.

The square root of 123664421 is about 11120.4505754039. The cubic root of 123664421 is about 498.2128477846.

The spelling of 123664421 in words is "one hundred twenty-three million, six hundred sixty-four thousand, four hundred twenty-one".