20497636 has 6 divisors (see below), whose sum is σ = 35870870. Its totient is φ = 10248816.

The previous prime is 20497621. The next prime is 20497639. The reversal of 20497636 is 63679402.

It can be written as a sum of positive squares in only one way, i.e., 20304036 + 193600 = 4506^2 + 440^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20497595 and 20497604.

It is not an unprimeable number, because it can be changed into a prime (20497639) by changing a digit.

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, 2562201 + ... + 2562208.

Almost surely, 2^20497636 is an apocalyptic number.

It is an amenable number.

20497636 is a deficient number, since it is larger than the sum of its proper divisors (15373234).

20497636 is a wasteful number, since it uses less digits than its factorization.

20497636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5124413 (or 5124411 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 37.

The square root of 20497636 is about 4527.4315014145. The cubic root of 20497636 is about 273.6746631441.

The spelling of 20497636 in words is "twenty million, four hundred ninety-seven thousand, six hundred thirty-six".