20831031 has 24 divisors (see below), whose sum is σ = 33817056. Its totient is φ = 12260160.

The previous prime is 20831017. The next prime is 20831051. The reversal of 20831031 is 13013802.

It is not a de Polignac number, because 20831031 - 2¹³ = 20822839 is a prime.

It is a super-2 number, since 2×20831031² = 867863705045922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20830995 and 20831013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20831051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1180 + ... + 6561.

It is an arithmetic number, because the mean of its divisors is an integer number (1409044).

Almost surely, 2^20831031 is an apocalyptic number.

20831031 is a deficient number, since it is larger than the sum of its proper divisors (12986025).

20831031 is a wasteful number, since it uses less digits than its factorization.

20831031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7783 (or 7780 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20831031 is about 4564.1024309277. The cubic root of 20831031 is about 275.1504675182.

Adding to 20831031 its reverse (13013802), we get a palindrome (33844833).

The spelling of 20831031 in words is "twenty million, eight hundred thirty-one thousand, thirty-one".