20111431 has 4 divisors (see below), whose sum is σ = 20175192. Its totient is φ = 20047672.

The previous prime is 20111411. The next prime is 20111447. The reversal of 20111431 is 13411102.

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 20111431 - 2⁷ = 20111303 is a prime.

It is a super-2 number, since 2×20111431² = 808939313735522, 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 (20111411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31405 + ... + 32038.

It is an arithmetic number, because the mean of its divisors is an integer number (5043798).

Almost surely, 2^20111431 is an apocalyptic number.

20111431 is a deficient number, since it is larger than the sum of its proper divisors (63761).

20111431 is an equidigital number, since it uses as much as digits as its factorization.

20111431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63760.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 20111431 is about 4484.5770146135. The cubic root of 20111431 is about 271.9449454245.

Adding to 20111431 its reverse (13411102), we get a palindrome (33522533).

The spelling of 20111431 in words is "twenty million, one hundred eleven thousand, four hundred thirty-one".