20404404331 has 4 divisors (see below), whose sum is σ = 20420017272. Its totient is φ = 20388791392.

The previous prime is 20404404313. The next prime is 20404404341. The reversal of 20404404331 is 13340440402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13340440402 = 2 ⋅6670220201.

It is a cyclic number.

It is not a de Polignac number, because 20404404331 - 2¹⁹ = 20403880043 is a prime.

It is a super-2 number, since 2×20404404331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20404404296 and 20404404305.

It is not an unprimeable number, because it can be changed into a prime (20404404311) 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, 7804510 + ... + 7807123.

It is an arithmetic number, because the mean of its divisors is an integer number (5105004318).

Almost surely, 2^20404404331 is an apocalyptic number.

20404404331 is a deficient number, since it is larger than the sum of its proper divisors (15612941).

20404404331 is a wasteful number, since it uses less digits than its factorization.

20404404331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15612940.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 20404404331 its reverse (13340440402), we get a palindrome (33744844733).

The spelling of 20404404331 in words is "twenty billion, four hundred four million, four hundred four thousand, three hundred thirty-one".