20731208 has 8 divisors (see below), whose sum is σ = 38871030. Its totient is φ = 10365600.

The previous prime is 20731189. The next prime is 20731231. The reversal of 20731208 is 80213702.

It can be written as a sum of positive squares in only one way, i.e., 11957764 + 8773444 = 3458^2 + 2962^2 .

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

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, 1295693 + ... + 1295708.

Almost surely, 2^20731208 is an apocalyptic number.

It is an amenable number.

20731208 is a deficient number, since it is larger than the sum of its proper divisors (18139822).

20731208 is a wasteful number, since it uses less digits than its factorization.

20731208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591407 (or 2591403 counting only the distinct ones).

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

The square root of 20731208 is about 4553.1536323739. The cubic root of 20731208 is about 274.7102535011.

The spelling of 20731208 in words is "twenty million, seven hundred thirty-one thousand, two hundred eight".