20736644 has 24 divisors (see below), whose sum is σ = 37900800. Its totient is φ = 9915840.

The previous prime is 20736623. The next prime is 20736647. The reversal of 20736644 is 44663702.

It is a self number, because there is not a number n which added to its sum of digits gives 20736644.

It is not an unprimeable number, because it can be changed into a prime (20736647) 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 in 7 ways as a sum of consecutive naturals, for example, 10097 + ... + 11975.

It is an arithmetic number, because the mean of its divisors is an integer number (1579200).

Almost surely, 2^20736644 is an apocalyptic number.

It is an amenable number.

20736644 is a deficient number, since it is larger than the sum of its proper divisors (17164156).

20736644 is a wasteful number, since it uses less digits than its factorization.

20736644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2003 (or 2001 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 32.

The square root of 20736644 is about 4553.7505421356. The cubic root of 20736644 is about 274.7342623036.

The spelling of 20736644 in words is "twenty million, seven hundred thirty-six thousand, six hundred forty-four".