20345143531 has 4 divisors (see below), whose sum is σ = 20401815600. Its totient is φ = 20288471464.

The previous prime is 20345143477. The next prime is 20345143571. The reversal of 20345143531 is 13534154302.

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 20345143531 - 2¹⁷ = 20345012459 is a prime.

It is a super-2 number, since 2×20345143531² (a number of 21 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 = 20345143493 and 20345143502.

It is not an unprimeable number, because it can be changed into a prime (20345143571) 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 3 ways as a sum of consecutive naturals, for example, 28335496 + ... + 28336213.

It is an arithmetic number, because the mean of its divisors is an integer number (5100453900).

Almost surely, 2^20345143531 is an apocalyptic number.

20345143531 is a deficient number, since it is larger than the sum of its proper divisors (56672069).

20345143531 is an equidigital number, since it uses as much as digits as its factorization.

20345143531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56672068.

The product of its (nonzero) digits is 21600, while the sum is 31.

Adding to 20345143531 its reverse (13534154302), we get a palindrome (33879297833).

The spelling of 20345143531 in words is "twenty billion, three hundred forty-five million, one hundred forty-three thousand, five hundred thirty-one".