20506305531 has 16 divisors (see below), whose sum is σ = 27932502528. Its totient is φ = 13375677600.

The previous prime is 20506305529. The next prime is 20506305577. The reversal of 20506305531 is 13550360502.

It is not a de Polignac number, because 20506305531 - 2¹ = 20506305529 is a prime.

It is a super-2 number, since 2×20506305531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20506304531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447841 + ... + 491501.

It is an arithmetic number, because the mean of its divisors is an integer number (1745781408).

Almost surely, 2^20506305531 is an apocalyptic number.

20506305531 is a deficient number, since it is larger than the sum of its proper divisors (7426196997).

20506305531 is a wasteful number, since it uses less digits than its factorization.

20506305531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47042.

The product of its (nonzero) digits is 13500, while the sum is 30.

The spelling of 20506305531 in words is "twenty billion, five hundred six million, three hundred five thousand, five hundred thirty-one".