20717828 has 12 divisors (see below), whose sum is σ = 38164560. Its totient is φ = 9813672.

The previous prime is 20717819. The next prime is 20717839. The reversal of 20717828 is 82871702.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136226 + ... + 136377.

It is an arithmetic number, because the mean of its divisors is an integer number (3180380).

Almost surely, 2^20717828 is an apocalyptic number.

It is an amenable number.

20717828 is a deficient number, since it is larger than the sum of its proper divisors (17446732).

20717828 is a wasteful number, since it uses less digits than its factorization.

20717828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272626 (or 272624 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 20717828 is about 4551.6840839408. The cubic root of 20717828 is about 274.6511411036.

The spelling of 20717828 in words is "twenty million, seven hundred seventeen thousand, eight hundred twenty-eight".