20345131 has 4 divisors (see below), whose sum is σ = 20381832. Its totient is φ = 20308432.

The previous prime is 20345093. The next prime is 20345161. The reversal of 20345131 is 13154302.

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 20345131 - 2⁹ = 20344619 is a prime.

It is a super-2 number, since 2×20345131² = 827848710814322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20345099 and 20345108.

It is not an unprimeable number, because it can be changed into a prime (20345161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17506 + ... + 18631.

It is an arithmetic number, because the mean of its divisors is an integer number (5095458).

Almost surely, 2^20345131 is an apocalyptic number.

20345131 is a deficient number, since it is larger than the sum of its proper divisors (36701).

20345131 is an equidigital number, since it uses as much as digits as its factorization.

20345131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36700.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 20345131 is about 4510.5577260467. The cubic root of 20345131 is about 272.9942482027.

Adding to 20345131 its reverse (13154302), we get a palindrome (33499433).

The spelling of 20345131 in words is "twenty million, three hundred forty-five thousand, one hundred thirty-one".