20647936 has 39 divisors (see below), whose sum is σ = 41880583. Its totient is φ = 10178560.

The previous prime is 20647933. The next prime is 20647943. The reversal of 20647936 is 63974602.

The square root of 20647936 is 4544.

It is a perfect power (a square), and thus also a powerful number.

It is a super-2 number, since 2×20647936² = 852674522120192, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20647895 and 20647904.

It is not an unprimeable number, because it can be changed into a prime (20647933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 290781 + ... + 290851.

Almost surely, 2^20647936 is an apocalyptic number.

20647936 is the 4544-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20647936

20647936 is an abundant number, since it is smaller than the sum of its proper divisors (21232647).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20647936 is an frugal number, since it uses more digits than its factorization.

20647936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 73 counting only the distinct ones).

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

The cubic root of 20647936 is about 274.3419461430.

It can be divided in two parts, 2064 and 7936, that added together give a 4-th power (10000 = 10⁴).

The spelling of 20647936 in words is "twenty million, six hundred forty-seven thousand, nine hundred thirty-six".