404431431221 has 4 divisors (see below), whose sum is σ = 405471101100. Its totient is φ = 403391761344.

The previous prime is 404431431191. The next prime is 404431431263. The reversal of 404431431221 is 122134134404.

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 83946370225 + 320485060996 = 289735^2 + 566114^2 .

It is a cyclic number.

It is not a de Polignac number, because 404431431221 - 2²⁶ = 404364322357 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 (404431401221) 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, 519834356 + ... + 519835133.

It is an arithmetic number, because the mean of its divisors is an integer number (101367775275).

Almost surely, 2^404431431221 is an apocalyptic number.

It is an amenable number.

404431431221 is a deficient number, since it is larger than the sum of its proper divisors (1039669879).

404431431221 is a wasteful number, since it uses less digits than its factorization.

404431431221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1039669878.

The product of its (nonzero) digits is 9216, while the sum is 29.

Adding to 404431431221 its reverse (122134134404), we get a palindrome (526565565625).

The spelling of 404431431221 in words is "four hundred four billion, four hundred thirty-one million, four hundred thirty-one thousand, two hundred twenty-one".