20511131125 has 32 divisors (see below), whose sum is σ = 27164243808. Its totient is φ = 15409152000.

The previous prime is 20511131093. The next prime is 20511131143. The reversal of 20511131125 is 52113111502.

It can be written as a sum of positive squares in 16 ways, for example, as 5153229796 + 15357901329 = 71786^2 + 123927^2 .

It is not a de Polignac number, because 20511131125 - 2⁵ = 20511131093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20511131096 and 20511131105.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 960565 + ... + 981685.

It is an arithmetic number, because the mean of its divisors is an integer number (848882619).

Almost surely, 2^20511131125 is an apocalyptic number.

20511131125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20511131125 is a deficient number, since it is larger than the sum of its proper divisors (6653112683).

20511131125 is a wasteful number, since it uses less digits than its factorization.

20511131125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21610 (or 21600 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 22.

Adding to 20511131125 its reverse (52113111502), we get a palindrome (72624242627).

The spelling of 20511131125 in words is "twenty billion, five hundred eleven million, one hundred thirty-one thousand, one hundred twenty-five".