420403421 has 4 divisors (see below), whose sum is σ = 445133052. Its totient is φ = 395673792.

The previous prime is 420403411. The next prime is 420403429. The reversal of 420403421 is 124304024.

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 138532900 + 281870521 = 11770^2 + 16789^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420403421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 420403393 and 420403402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420403429) 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, 12364790 + ... + 12364823.

It is an arithmetic number, because the mean of its divisors is an integer number (111283263).

Almost surely, 2^420403421 is an apocalyptic number.

It is an amenable number.

420403421 is a deficient number, since it is larger than the sum of its proper divisors (24729631).

420403421 is a wasteful number, since it uses less digits than its factorization.

420403421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24729630.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 420403421 is about 20503.7416341506. The cubic root of 420403421 is about 749.1269372615.

Adding to 420403421 its reverse (124304024), we get a palindrome (544707445).

The spelling of 420403421 in words is "four hundred twenty million, four hundred three thousand, four hundred twenty-one".