20811023131 has 4 divisors (see below), whose sum is σ = 20812286664. Its totient is φ = 20809759600.

The previous prime is 20811023069. The next prime is 20811023153. The reversal of 20811023131 is 13132011802.

It is a happy number.

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 20811023131 - 2⁷ = 20811023003 is a prime.

It is a super-2 number, since 2×20811023131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20811023731) 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, 606730 + ... + 640111.

It is an arithmetic number, because the mean of its divisors is an integer number (5203071666).

Almost surely, 2^20811023131 is an apocalyptic number.

20811023131 is a deficient number, since it is larger than the sum of its proper divisors (1263533).

20811023131 is a wasteful number, since it uses less digits than its factorization.

20811023131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1263532.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 20811023131 its reverse (13132011802), we get a palindrome (33943034933).

The spelling of 20811023131 in words is "twenty billion, eight hundred eleven million, twenty-three thousand, one hundred thirty-one".