20315566 has 8 divisors (see below), whose sum is σ = 30631824. Its totient is φ = 10104960.

The previous prime is 20315557. The next prime is 20315569. The reversal of 20315566 is 66551302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20315569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25930 + ... + 26701.

It is an arithmetic number, because the mean of its divisors is an integer number (3828978).

Almost surely, 2^20315566 is an apocalyptic number.

20315566 is a deficient number, since it is larger than the sum of its proper divisors (10316258).

20315566 is a wasteful number, since it uses less digits than its factorization.

20315566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52826.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 20315566 is about 4507.2792236559. The cubic root of 20315566 is about 272.8619481180.

Adding to 20315566 its reverse (66551302), we get a palindrome (86866868).

The spelling of 20315566 in words is "twenty million, three hundred fifteen thousand, five hundred sixty-six".