13499883721 has 3 divisors (see below), whose sum is σ = 13499999911. Its totient is φ = 13499767532.

The previous prime is 13499883713. The next prime is 13499883763. The reversal of 13499883721 is 12738899431.

It is a happy number.

The square root of 13499883721 is 116189.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1935032121 + 11564851600 = 43989^2 + 107540^2 .

It is not a de Polignac number, because 13499883721 - 2³ = 13499883713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13499883421) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 58095 + ... + 174283.

Almost surely, 2^13499883721 is an apocalyptic number.

13499883721 is the 116189-th square number.

13499883721 is the 58095-th centered octagonal number.

It is an amenable number.

13499883721 is a deficient number, since it is larger than the sum of its proper divisors (116190).

13499883721 is an frugal number, since it uses more digits than its factorization.

13499883721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232378 (or 116189 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 55.

The spelling of 13499883721 in words is "thirteen billion, four hundred ninety-nine million, eight hundred eighty-three thousand, seven hundred twenty-one".