20209568 has 12 divisors (see below), whose sum is σ = 39787650. Its totient is φ = 10104768.

The previous prime is 20209561. The next prime is 20209591. The reversal of 20209568 is 86590202.

It can be written as a sum of positive squares in only one way, i.e., 18215824 + 1993744 = 4268^2 + 1412^2 .

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 631549 = 20209568 / (2 + 0 + 2 + 0 + 9 + 5 + 6 + 8).

It is not an unprimeable number, because it can be changed into a prime (20209561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315743 + ... + 315806.

Almost surely, 2^20209568 is an apocalyptic number.

It is an amenable number.

20209568 is a deficient number, since it is larger than the sum of its proper divisors (19578082).

20209568 is an equidigital number, since it uses as much as digits as its factorization.

20209568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631559 (or 631551 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 20209568 is about 4495.5053108633. The cubic root of 20209568 is about 272.3865610933.

The spelling of 20209568 in words is "twenty million, two hundred nine thousand, five hundred sixty-eight".