20131131224 has 8 divisors (see below), whose sum is σ = 37745871060. Its totient is φ = 10065565608.

The previous prime is 20131131203. The next prime is 20131131239. The reversal of 20131131224 is 42213113102.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 20131131196 and 20131131205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1258195694 + ... + 1258195709.

Almost surely, 2^20131131224 is an apocalyptic number.

It is an amenable number.

20131131224 is a deficient number, since it is larger than the sum of its proper divisors (17614739836).

20131131224 is a wasteful number, since it uses less digits than its factorization.

20131131224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2516391409 (or 2516391405 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 20131131224 its reverse (42213113102), we get a palindrome (62344244326).

The spelling of 20131131224 in words is "twenty billion, one hundred thirty-one million, one hundred thirty-one thousand, two hundred twenty-four".