20115431 has 6 divisors (see below), whose sum is σ = 23399640. Its totient is φ = 17241756.

The previous prime is 20115413. The next prime is 20115439. The reversal of 20115431 is 13451102.

It is not a de Polignac number, because 20115431 - 2⁶ = 20115367 is a prime.

It is a super-2 number, since 2×20115431² = 809261128631522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20115439) 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 5 ways as a sum of consecutive naturals, for example, 205211 + ... + 205308.

It is an arithmetic number, because the mean of its divisors is an integer number (3899940).

Almost surely, 2^20115431 is an apocalyptic number.

20115431 is a deficient number, since it is larger than the sum of its proper divisors (3284209).

20115431 is an equidigital number, since it uses as much as digits as its factorization.

20115431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410533 (or 410526 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 20115431 is about 4485.0229653816. The cubic root of 20115431 is about 271.9629734417.

Adding to 20115431 its reverse (13451102), we get a palindrome (33566533).

The spelling of 20115431 in words is "twenty million, one hundred fifteen thousand, four hundred thirty-one".