20928644 has 24 divisors (see below), whose sum is σ = 40295136. Its totient is φ = 9510600.

The previous prime is 20928637. The next prime is 20928647. The reversal of 20928644 is 44682902.

It is not an unprimeable number, because it can be changed into a prime (20928647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3359 + ... + 7289.

It is an arithmetic number, because the mean of its divisors is an integer number (1678964).

Almost surely, 2^20928644 is an apocalyptic number.

It is an amenable number.

20928644 is a deficient number, since it is larger than the sum of its proper divisors (19366492).

20928644 is a wasteful number, since it uses less digits than its factorization.

20928644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3968 (or 3944 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 20928644 is about 4574.7834921447. The cubic root of 20928644 is about 275.5795776501.

The spelling of 20928644 in words is "twenty million, nine hundred twenty-eight thousand, six hundred forty-four".