20512261540 has 24 divisors (see below), whose sum is σ = 45609617592. Its totient is φ = 7722263040.

The previous prime is 20512261537. The next prime is 20512261541. The reversal of 20512261540 is 4516221502.

It can be written as a sum of positive squares in 4 ways, for example, as 3138912676 + 17373348864 = 56026^2 + 131808^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20512261499 and 20512261508.

It is not an unprimeable number, because it can be changed into a prime (20512261541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30164751 + ... + 30165430.

It is an arithmetic number, because the mean of its divisors is an integer number (1900400733).

Almost surely, 2^20512261540 is an apocalyptic number.

20512261540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20512261540 is an abundant number, since it is smaller than the sum of its proper divisors (25097356052).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20512261540 is a wasteful number, since it uses less digits than its factorization.

20512261540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60330207 (or 60330205 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

It can be divided in two parts, 205122 and 61540, that added together give a palindrome (266662).

The spelling of 20512261540 in words is "twenty billion, five hundred twelve million, two hundred sixty-one thousand, five hundred forty".