13509649971 has 24 divisors (see below), whose sum is σ = 21249306000. Its totient is φ = 8238186432.

The previous prime is 13509649963. The next prime is 13509650017. The reversal of 13509649971 is 17994690531.

13509649971 is a `hidden beast` number, since 1 + 3 + 509 + 6 + 49 + 97 + 1 = 666.

It is not a de Polignac number, because 13509649971 - 2³ = 13509649963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13509649921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1357176 + ... + 1367093.

It is an arithmetic number, because the mean of its divisors is an integer number (885387750).

Almost surely, 2^13509649971 is an apocalyptic number.

13509649971 is a deficient number, since it is larger than the sum of its proper divisors (7739656029).

13509649971 is a wasteful number, since it uses less digits than its factorization.

13509649971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2724323 (or 2724320 counting only the distinct ones).

The product of its (nonzero) digits is 1837080, while the sum is 54.

The spelling of 13509649971 in words is "thirteen billion, five hundred nine million, six hundred forty-nine thousand, nine hundred seventy-one".