20731316 has 6 divisors (see below), whose sum is σ = 36279810. Its totient is φ = 10365656.

The previous prime is 20731309. The next prime is 20731327. The reversal of 20731316 is 61313702.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 119716 = 4540^2 + 346^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20731291 and 20731300.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2591411 + ... + 2591418.

It is an arithmetic number, because the mean of its divisors is an integer number (6046635).

Almost surely, 2^20731316 is an apocalyptic number.

It is an amenable number.

20731316 is a deficient number, since it is larger than the sum of its proper divisors (15548494).

20731316 is a wasteful number, since it uses less digits than its factorization.

20731316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5182833 (or 5182831 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 20731316 is about 4553.1654922702. The cubic root of 20731316 is about 274.7107305381.

The spelling of 20731316 in words is "twenty million, seven hundred thirty-one thousand, three hundred sixteen".