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20731031 = 43482117
BaseRepresentation
bin100111100010…
…1010010010111
31110000020121222
41033011102113
520301343111
62020200555
7341132216
oct117052227
943006558
1020731031
111077a592
126b3915b
1343ab0a9
142a7907d
151c477db
hex13c5497

20731031 has 4 divisors (see below), whose sum is σ = 21213192. Its totient is φ = 20248872.

The previous prime is 20731001. The next prime is 20731043. The reversal of 20731031 is 13013702.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20731031 - 214 = 20714647 is a prime.

It is a super-2 number, since 2×207310312 = 859551292645922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241016 + ... + 241101.

It is an arithmetic number, because the mean of its divisors is an integer number (5303298).

Almost surely, 220731031 is an apocalyptic number.

20731031 is a deficient number, since it is larger than the sum of its proper divisors (482161).

20731031 is an equidigital number, since it uses as much as digits as its factorization.

20731031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482160.

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 20731031 is about 4553.1341952550. The cubic root of 20731031 is about 274.7094716870.

Adding to 20731031 its reverse (13013702), we get a palindrome (33744733).

The spelling of 20731031 in words is "twenty million, seven hundred thirty-one thousand, thirty-one".

Divisors: 1 43 482117 20731031