20315505 has 32 divisors (see below), whose sum is σ = 37407744. Its totient is φ = 9222336.

The previous prime is 20315497. The next prime is 20315507. The reversal of 20315505 is 50551302.

20315505 is nontrivially palindromic in base 4.

It is not a de Polignac number, because 20315505 - 2³ = 20315497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (20315507) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16522 + ... + 17708.

It is an arithmetic number, because the mean of its divisors is an integer number (1168992).

Almost surely, 2^20315505 is an apocalyptic number.

It is an amenable number.

20315505 is a deficient number, since it is larger than the sum of its proper divisors (17092239).

20315505 is a wasteful number, since it uses less digits than its factorization.

20315505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1365.

The product of its (nonzero) digits is 750, while the sum is 21.

The square root of 20315505 is about 4507.2724568191. The cubic root of 20315505 is about 272.8616750172.

Adding to 20315505 its reverse (50551302), we get a palindrome (70866807).

The spelling of 20315505 in words is "twenty million, three hundred fifteen thousand, five hundred five".