20312447 has 4 divisors (see below), whose sum is σ = 20325960. Its totient is φ = 20298936.

The previous prime is 20312443. The next prime is 20312483. The reversal of 20312447 is 74421302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20312447 - 2² = 20312443 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20312443) 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, 4172 + ... + 7617.

It is an arithmetic number, because the mean of its divisors is an integer number (5081490).

Almost surely, 2^20312447 is an apocalyptic number.

20312447 is a deficient number, since it is larger than the sum of its proper divisors (13513).

20312447 is a wasteful number, since it uses less digits than its factorization.

20312447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13512.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 20312447 is about 4506.9332145041. The cubic root of 20312447 is about 272.8479834571.

Adding to 20312447 its reverse (74421302), we get a palindrome (94733749).

The spelling of 20312447 in words is "twenty million, three hundred twelve thousand, four hundred forty-seven".