13171721540 has 12 divisors (see below), whose sum is σ = 27660615276. Its totient is φ = 5268688608.

The previous prime is 13171721527. The next prime is 13171721543. The reversal of 13171721540 is 4512717131.

It can be written as a sum of positive squares in 2 ways, for example, as 6450017344 + 6721704196 = 80312^2 + 81986^2 .

It is a junction number, because it is equal to n+sod(n) for n = 13171721497 and 13171721506.

It is not an unprimeable number, because it can be changed into a prime (13171721543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 329293019 + ... + 329293058.

It is an arithmetic number, because the mean of its divisors is an integer number (2305051273).

Almost surely, 2^13171721540 is an apocalyptic number.

13171721540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13171721540 is an abundant number, since it is smaller than the sum of its proper divisors (14488893736).

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

13171721540 is a wasteful number, since it uses less digits than its factorization.

13171721540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658586086 (or 658586084 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 32.

The spelling of 13171721540 in words is "thirteen billion, one hundred seventy-one million, seven hundred twenty-one thousand, five hundred forty".