404242220440021 has 4 divisors (see below), whose sum is σ = 404242370870112. Its totient is φ = 404242070009932.

The previous prime is 404242220440013. The next prime is 404242220440073. The reversal of 404242220440021 is 120044022242404.

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 not a de Polignac number, because 404242220440021 - 2³ = 404242220440013 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 (404242220440921) 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, 71109481 + ... + 76583566.

It is an arithmetic number, because the mean of its divisors is an integer number (101060592717528).

Almost surely, 2^{404242220440021} is an apocalyptic number.

It is an amenable number.

404242220440021 is a deficient number, since it is larger than the sum of its proper divisors (150430091).

404242220440021 is a wasteful number, since it uses less digits than its factorization.

404242220440021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150430090.

The product of its (nonzero) digits is 32768, while the sum is 31.

Adding to 404242220440021 its reverse (120044022242404), we get a palindrome (524286242682425).

The spelling of 404242220440021 in words is "four hundred four trillion, two hundred forty-two billion, two hundred twenty million, four hundred forty thousand, twenty-one".