20531401443431 has 4 divisors (see below), whose sum is σ = 20538220244664. Its totient is φ = 20524582642200.

The previous prime is 20531401443409. The next prime is 20531401443463. The reversal of 20531401443431 is 13434410413502.

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-20531401443431 is a prime.

It is a super-2 number, since 2×20531401443431² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20531401443391 and 20531401443400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20531401463431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3409396100 + ... + 3409402121.

It is an arithmetic number, because the mean of its divisors is an integer number (5134555061166).

Almost surely, 2^{20531401443431} is an apocalyptic number.

20531401443431 is a deficient number, since it is larger than the sum of its proper divisors (6818801233).

20531401443431 is an equidigital number, since it uses as much as digits as its factorization.

20531401443431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6818801232.

The product of its (nonzero) digits is 69120, while the sum is 35.

Adding to 20531401443431 its reverse (13434410413502), we get a palindrome (33965811856933).

The spelling of 20531401443431 in words is "twenty trillion, five hundred thirty-one billion, four hundred one million, four hundred forty-three thousand, four hundred thirty-one".