404212421 has 4 divisors (see below), whose sum is σ = 407298144. Its totient is φ = 401126700.

The previous prime is 404212409. The next prime is 404212423. The reversal of 404212421 is 124212404.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-404212421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 404212393 and 404212402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404212423) 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, 1542665 + ... + 1542926.

It is an arithmetic number, because the mean of its divisors is an integer number (101824536).

Almost surely, 2^404212421 is an apocalyptic number.

It is an amenable number.

404212421 is a deficient number, since it is larger than the sum of its proper divisors (3085723).

404212421 is a wasteful number, since it uses less digits than its factorization.

404212421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3085722.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 404212421 is about 20105.0347177019. The cubic root of 404212421 is about 739.3837217437.

Adding to 404212421 its reverse (124212404), we get a palindrome (528424825).

The spelling of 404212421 in words is "four hundred four million, two hundred twelve thousand, four hundred twenty-one".