820740013540 has 12 divisors (see below), whose sum is σ = 1723554028476. Its totient is φ = 328296005408.

The previous prime is 820740013529. The next prime is 820740013543. The reversal of 820740013540 is 45310047028.

It can be written as a sum of positive squares in 2 ways, for example, as 598763344804 + 221976668736 = 773798^2 + 471144^2 .

It is a super-2 number, since 2×820740013540² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 820740013496 and 820740013505.

It is not an unprimeable number, because it can be changed into a prime (820740013543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20518500319 + ... + 20518500358.

It is an arithmetic number, because the mean of its divisors is an integer number (143629502373).

Almost surely, 2^820740013540 is an apocalyptic number.

It is an amenable number.

820740013540 is an abundant number, since it is smaller than the sum of its proper divisors (902814014936).

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

820740013540 is a wasteful number, since it uses less digits than its factorization.

820740013540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41037000686 (or 41037000684 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 34.

The spelling of 820740013540 in words is "eight hundred twenty billion, seven hundred forty million, thirteen thousand, five hundred forty".