20401443431 has 4 divisors (see below), whose sum is σ = 20952833832. Its totient is φ = 19850053032.

The previous prime is 20401443427. The next prime is 20401443451. The reversal of 20401443431 is 13434410402.

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 20401443431 - 2² = 20401443427 is a prime.

It is a super-2 number, since 2×20401443431² (a number of 21 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 20401443431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401443451) 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, 275695145 + ... + 275695218.

It is an arithmetic number, because the mean of its divisors is an integer number (5238208458).

Almost surely, 2^20401443431 is an apocalyptic number.

20401443431 is a deficient number, since it is larger than the sum of its proper divisors (551390401).

20401443431 is an equidigital number, since it uses as much as digits as its factorization.

20401443431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551390400.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 20401443431 its reverse (13434410402), we get a palindrome (33835853833).

The spelling of 20401443431 in words is "twenty billion, four hundred one million, four hundred forty-three thousand, four hundred thirty-one".