13131555649 has 3 divisors (see below), whose sum is σ = 13131670243. Its totient is φ = 13131441056.

The previous prime is 13131555607. The next prime is 13131555691. The reversal of 13131555649 is 94655513131.

The square root of 13131555649 is 114593.

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 is an interprime number because it is at equal distance from previous prime (13131555607) and next prime (13131555691).

It can be written as a sum of positive squares in only one way, i.e., 12666377025 + 465178624 = 112545^2 + 21568^2 .

It is not a de Polignac number, because 13131555649 - 2¹¹ = 13131553601 is a prime.

It is a super-2 number, since 2×13131555649² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13131553649) 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, 57297 + ... + 171889.

Almost surely, 2^13131555649 is an apocalyptic number.

13131555649 is the 114593-rd square number.

13131555649 is the 57297-th centered octagonal number.

It is an amenable number.

13131555649 is a deficient number, since it is larger than the sum of its proper divisors (114594).

13131555649 is an frugal number, since it uses more digits than its factorization.

13131555649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229186 (or 114593 counting only the distinct ones).

The product of its digits is 243000, while the sum is 43.

The spelling of 13131555649 in words is "thirteen billion, one hundred thirty-one million, five hundred fifty-five thousand, six hundred forty-nine".