20311203240431 has 4 divisors (see below), whose sum is σ = 20435811849432. Its totient is φ = 20186594631432.

The previous prime is 20311203240413. The next prime is 20311203240443. The reversal of 20311203240431 is 13404230211302.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20311203240431 is a prime.

It is a super-2 number, since 2×20311203240431² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20311203240431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311203240401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62304304256 + ... + 62304304581.

It is an arithmetic number, because the mean of its divisors is an integer number (5108952962358).

Almost surely, 2^{20311203240431} is an apocalyptic number.

20311203240431 is a deficient number, since it is larger than the sum of its proper divisors (124608609001).

20311203240431 is a wasteful number, since it uses less digits than its factorization.

20311203240431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124608609000.

The product of its (nonzero) digits is 3456, while the sum is 26.

Adding to 20311203240431 its reverse (13404230211302), we get a palindrome (33715433451733).

The spelling of 20311203240431 in words is "twenty trillion, three hundred eleven billion, two hundred three million, two hundred forty thousand, four hundred thirty-one".