20542205531 has 4 divisors (see below), whose sum is σ = 20568308232. Its totient is φ = 20516102832.

The previous prime is 20542205513. The next prime is 20542205549. The reversal of 20542205531 is 13550224502.

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

It is an interprime number because it is at equal distance from previous prime (20542205513) and next prime (20542205549).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20542205531 is a prime.

It is a super-2 number, since 2×20542205531² (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 = 20542205494 and 20542205503.

It is not an unprimeable number, because it can be changed into a prime (20542205591) 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, 13050170 + ... + 13051743.

It is an arithmetic number, because the mean of its divisors is an integer number (5142077058).

Almost surely, 2^20542205531 is an apocalyptic number.

20542205531 is a deficient number, since it is larger than the sum of its proper divisors (26102701).

20542205531 is an equidigital number, since it uses as much as digits as its factorization.

20542205531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26102700.

The product of its (nonzero) digits is 12000, while the sum is 29.

The spelling of 20542205531 in words is "twenty billion, five hundred forty-two million, two hundred five thousand, five hundred thirty-one".