20309031 has 6 divisors (see below), whose sum is σ = 29335280. Its totient is φ = 13539348.

The previous prime is 20308993. The next prime is 20309057. The reversal of 20309031 is 13090302.

It is not a de Polignac number, because 20309031 - 2²² = 16114727 is a prime.

It is a super-2 number, since 2×20309031² = 824913480317922, 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 = 20308995 and 20309013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309071) 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 5 ways as a sum of consecutive naturals, for example, 1128271 + ... + 1128288.

Almost surely, 2^20309031 is an apocalyptic number.

20309031 is a deficient number, since it is larger than the sum of its proper divisors (9026249).

20309031 is a wasteful number, since it uses less digits than its factorization.

20309031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2256565 (or 2256562 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

The square root of 20309031 is about 4506.5542269011. The cubic root of 20309031 is about 272.8326874013.

Adding to 20309031 its reverse (13090302), we get a palindrome (33399333).

The spelling of 20309031 in words is "twenty million, three hundred nine thousand, thirty-one".