420440421 has 4 divisors (see below), whose sum is σ = 560587232. Its totient is φ = 280293612.

The previous prime is 420440411. The next prime is 420440429. The reversal of 420440421 is 124044024.

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 not a de Polignac number, because 420440421 - 2⁶ = 420440357 is a prime.

It is a super-2 number, since 2×420440421² = 353540295221314482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420440429) 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, 70073401 + ... + 70073406.

It is an arithmetic number, because the mean of its divisors is an integer number (140146808).

Almost surely, 2^420440421 is an apocalyptic number.

It is an amenable number.

420440421 is a deficient number, since it is larger than the sum of its proper divisors (140146811).

420440421 is a wasteful number, since it uses less digits than its factorization.

420440421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140146810.

The product of its (nonzero) digits is 1024, while the sum is 21.

The square root of 420440421 is about 20504.6438886414. The cubic root of 420440421 is about 749.1489136792.

Adding to 420440421 its reverse (124044024), we get a palindrome (544484445).

The spelling of 420440421 in words is "four hundred twenty million, four hundred forty thousand, four hundred twenty-one".