420543721 has 8 divisors (see below), whose sum is σ = 459273024. Its totient is φ = 382725840.

The previous prime is 420543689. The next prime is 420543743. The reversal of 420543721 is 127345024.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 420543721 - 2⁵ = 420543689 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 420543721.

It is not an unprimeable number, because it can be changed into a prime (420543421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 226891 + ... + 228736.

It is an arithmetic number, because the mean of its divisors is an integer number (57409128).

Almost surely, 2^420543721 is an apocalyptic number.

It is an amenable number.

420543721 is a deficient number, since it is larger than the sum of its proper divisors (38729303).

420543721 is a wasteful number, since it uses less digits than its factorization.

420543721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455711.

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 420543721 is about 20507.1626755141. The cubic root of 420543721 is about 749.2102626377.

Adding to 420543721 its reverse (127345024), we get a palindrome (547888745).

The spelling of 420543721 in words is "four hundred twenty million, five hundred forty-three thousand, seven hundred twenty-one".