421840407 has 4 divisors (see below), whose sum is σ = 562453880. Its totient is φ = 281226936.

The previous prime is 421840381. The next prime is 421840421. The reversal of 421840407 is 704048124.

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

It is not a de Polignac number, because 421840407 - 2¹⁸ = 421578263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421840427) 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, 70306732 + ... + 70306737.

It is an arithmetic number, because the mean of its divisors is an integer number (140613470).

Almost surely, 2^421840407 is an apocalyptic number.

421840407 is a deficient number, since it is larger than the sum of its proper divisors (140613473).

421840407 is a wasteful number, since it uses less digits than its factorization.

421840407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140613472.

The product of its (nonzero) digits is 7168, while the sum is 30.

The square root of 421840407 is about 20538.7537840055. The cubic root of 421840407 is about 749.9794998841.

The spelling of 421840407 in words is "four hundred twenty-one million, eight hundred forty thousand, four hundred seven".