423665521 has 4 divisors (see below), whose sum is σ = 423964672. Its totient is φ = 423366372.

The previous prime is 423665509. The next prime is 423665527. The reversal of 423665521 is 125566324.

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 a cyclic number.

It is not a de Polignac number, because 423665521 - 2⁷ = 423665393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (423665527) 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, 147441 + ... + 150286.

It is an arithmetic number, because the mean of its divisors is an integer number (105991168).

Almost surely, 2^423665521 is an apocalyptic number.

It is an amenable number.

423665521 is a deficient number, since it is larger than the sum of its proper divisors (299151).

423665521 is a wasteful number, since it uses less digits than its factorization.

423665521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299150.

The product of its digits is 43200, while the sum is 34.

The square root of 423665521 is about 20583.1368114775. The cubic root of 423665521 is about 751.0595519096.

The spelling of 423665521 in words is "four hundred twenty-three million, six hundred sixty-five thousand, five hundred twenty-one".