423440643 has 4 divisors (see below), whose sum is σ = 564587528. Its totient is φ = 282293760.

The previous prime is 423440621. The next prime is 423440657. The reversal of 423440643 is 346044324.

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

It is not a de Polignac number, because 423440643 - 2⁸ = 423440387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 423440643.

It is not an unprimeable number, because it can be changed into a prime (423440243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70573438 + ... + 70573443.

It is an arithmetic number, because the mean of its divisors is an integer number (141146882).

Almost surely, 2^423440643 is an apocalyptic number.

423440643 is a deficient number, since it is larger than the sum of its proper divisors (141146885).

423440643 is a wasteful number, since it uses less digits than its factorization.

423440643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141146884.

The product of its (nonzero) digits is 27648, while the sum is 30.

The square root of 423440643 is about 20577.6734107625. The cubic root of 423440643 is about 750.9266430831.

Adding to 423440643 its reverse (346044324), we get a palindrome (769484967).

The spelling of 423440643 in words is "four hundred twenty-three million, four hundred forty thousand, six hundred forty-three".