20312505 has 32 divisors (see below), whose sum is σ = 36297600. Its totient is φ = 10777536.

The previous prime is 20312497. The next prime is 20312531. The reversal of 20312505 is 50521302.

It is a happy number.

It is not a de Polignac number, because 20312505 - 2³ = 20312497 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50967 + ... + 51363.

It is an arithmetic number, because the mean of its divisors is an integer number (1134300).

Almost surely, 2^20312505 is an apocalyptic number.

It is an amenable number.

20312505 is a deficient number, since it is larger than the sum of its proper divisors (15985095).

20312505 is a wasteful number, since it uses less digits than its factorization.

20312505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20312505 is about 4506.9396490301. The cubic root of 20312505 is about 272.8482431528.

Adding to 20312505 its reverse (50521302), we get a palindrome (70833807).

The spelling of 20312505 in words is "twenty million, three hundred twelve thousand, five hundred five".