20806736 has 10 divisors (see below), whose sum is σ = 40313082. Its totient is φ = 10403360.

The previous prime is 20806733. The next prime is 20806741. The reversal of 20806736 is 63760802.

It can be written as a sum of positive squares in only one way, i.e., 17272336 + 3534400 = 4156^2 + 1880^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20806733) 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 as a sum of consecutive naturals, namely, 650195 + ... + 650226.

Almost surely, 2^20806736 is an apocalyptic number.

It is an amenable number.

20806736 is a deficient number, since it is larger than the sum of its proper divisors (19506346).

20806736 is a wasteful number, since it uses less digits than its factorization.

20806736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1300429 (or 1300423 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20806736 is about 4561.4401234698. The cubic root of 20806736 is about 275.0434575949.

The spelling of 20806736 in words is "twenty million, eight hundred six thousand, seven hundred thirty-six".