20581051531 has 4 divisors (see below), whose sum is σ = 20969373312. Its totient is φ = 20192729752.

The previous prime is 20581051529. The next prime is 20581051537. The reversal of 20581051531 is 13515018502.

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 20581051531 - 2¹ = 20581051529 is a prime.

It is a super-2 number, since 2×20581051531² (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 = 20581051493 and 20581051502.

It is not an unprimeable number, because it can be changed into a prime (20581051537) 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 3 ways as a sum of consecutive naturals, for example, 194160811 + ... + 194160916.

It is an arithmetic number, because the mean of its divisors is an integer number (5242343328).

Almost surely, 2^20581051531 is an apocalyptic number.

20581051531 is a deficient number, since it is larger than the sum of its proper divisors (388321781).

20581051531 is an equidigital number, since it uses as much as digits as its factorization.

20581051531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388321780.

The product of its (nonzero) digits is 6000, while the sum is 31.

The spelling of 20581051531 in words is "twenty billion, five hundred eighty-one million, fifty-one thousand, five hundred thirty-one".