13249671721 has 16 divisors (see below), whose sum is σ = 15579627840. Its totient is φ = 11108905920.

The previous prime is 13249671671. The next prime is 13249671727. The reversal of 13249671721 is 12717694231.

It is a cyclic number.

It is not a de Polignac number, because 13249671721 - 2⁷ = 13249671593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13249671727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126475 + ... + 206143.

It is an arithmetic number, because the mean of its divisors is an integer number (973726740).

Almost surely, 2^13249671721 is an apocalyptic number.

13249671721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13249671721 is a deficient number, since it is larger than the sum of its proper divisors (2329956119).

13249671721 is a wasteful number, since it uses less digits than its factorization.

13249671721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80856.

The product of its digits is 127008, while the sum is 43.

The spelling of 13249671721 in words is "thirteen billion, two hundred forty-nine million, six hundred seventy-one thousand, seven hundred twenty-one".