20831636 has 12 divisors (see below), whose sum is σ = 41663328. Its totient is φ = 8927832.

The previous prime is 20831621. The next prime is 20831639. The reversal of 20831636 is 63613802.

20831636 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 20831599 and 20831608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20831639) 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, 371966 + ... + 372021.

It is an arithmetic number, because the mean of its divisors is an integer number (3471944).

Almost surely, 2^20831636 is an apocalyptic number.

It is an amenable number.

20831636 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20831636 is a wasteful number, since it uses less digits than its factorization.

20831636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743998 (or 743996 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20831636 is about 4564.1687085383. The cubic root of 20831636 is about 275.1531312434.

The spelling of 20831636 in words is "twenty million, eight hundred thirty-one thousand, six hundred thirty-six".