13674729721 has 9 divisors (see below), whose sum is σ = 13755067599. Its totient is φ = 13594860384.

The previous prime is 13674729659. The next prime is 13674729727. The reversal of 13674729721 is 12792747631.

The square root of 13674729721 is 116939.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3687525625 + 9987204096 = 60725^2 + 99936^2 .

It is not a de Polignac number, because 13674729721 - 2²⁷ = 13540511993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13674729727) 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 8 ways as a sum of consecutive naturals, for example, 39408270 + ... + 39408616.

Almost surely, 2^13674729721 is an apocalyptic number.

13674729721 is the 116939-th square number.

13674729721 is the 58470-th centered octagonal number.

It is an amenable number.

13674729721 is a deficient number, since it is larger than the sum of its proper divisors (80337878).

13674729721 is an frugal number, since it uses more digits than its factorization.

13674729721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368 (or 684 counting only the distinct ones).

The product of its digits is 889056, while the sum is 49.

Multiplying 13674729721 by its sum of digits (49), we get a square (670061756329 = 818573²).

The spelling of 13674729721 in words is "thirteen billion, six hundred seventy-four million, seven hundred twenty-nine thousand, seven hundred twenty-one".