20731028 has 6 divisors (see below), whose sum is σ = 36279306. Its totient is φ = 10365512.

The previous prime is 20731001. The next prime is 20731043. The reversal of 20731028 is 82013702.

It can be written as a sum of positive squares in only one way, i.e., 14961424 + 5769604 = 3868^2 + 2402^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20730994 and 20731012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2591375 + ... + 2591382.

It is an arithmetic number, because the mean of its divisors is an integer number (6046551).

Almost surely, 2^20731028 is an apocalyptic number.

It is an amenable number.

20731028 is a deficient number, since it is larger than the sum of its proper divisors (15548278).

20731028 is a wasteful number, since it uses less digits than its factorization.

20731028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5182761 (or 5182759 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20731028 is about 4553.1338658115. The cubic root of 20731028 is about 274.7094584359.

The spelling of 20731028 in words is "twenty million, seven hundred thirty-one thousand, twenty-eight".