420523643 has 4 divisors (see below), whose sum is σ = 422199288. Its totient is φ = 418848000.

The previous prime is 420523603. The next prime is 420523661. The reversal of 420523643 is 346325024.

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

It is a cyclic number.

It is not a de Polignac number, because 420523643 - 2⁸ = 420523387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (420523603) 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, 837446 + ... + 837947.

It is an arithmetic number, because the mean of its divisors is an integer number (105549822).

Almost surely, 2^420523643 is an apocalyptic number.

420523643 is a deficient number, since it is larger than the sum of its proper divisors (1675645).

420523643 is a wasteful number, since it uses less digits than its factorization.

420523643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1675644.

The product of its (nonzero) digits is 17280, while the sum is 29.

The square root of 420523643 is about 20506.6731333973. The cubic root of 420523643 is about 749.1983392773.

Adding to 420523643 its reverse (346325024), we get a palindrome (766848667).

The spelling of 420523643 in words is "four hundred twenty million, five hundred twenty-three thousand, six hundred forty-three".