20728964 has 12 divisors (see below), whose sum is σ = 36321600. Its totient is φ = 10351368.

The previous prime is 20728963. The next prime is 20728969. The reversal of 20728964 is 46982702.

It is not an unprimeable number, because it can be changed into a prime (20728963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 857 + ... + 6495.

It is an arithmetic number, because the mean of its divisors is an integer number (3026800).

Almost surely, 2^20728964 is an apocalyptic number.

It is an amenable number.

20728964 is a deficient number, since it is larger than the sum of its proper divisors (15592636).

20728964 is a wasteful number, since it uses less digits than its factorization.

20728964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6562 (or 6560 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 20728964 is about 4552.9072030956. The cubic root of 20728964 is about 274.7003413588.

The spelling of 20728964 in words is "twenty million, seven hundred twenty-eight thousand, nine hundred sixty-four".