13781116449 has 27 divisors (see below), whose sum is σ = 20146474803. Its totient is φ = 9077765904.

The previous prime is 13781116429. The next prime is 13781116457. The reversal of 13781116449 is 94461118731.

The square root of 13781116449 is 117393.

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

13781116449 is a `hidden beast` number, since 13 + 7 + 81 + 116 + 449 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9605372049 + 4175744400 = 98007^2 + 64620^2 .

It is not a de Polignac number, because 13781116449 - 2⁵ = 13781116417 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13781116429) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 38387332 + ... + 38387690.

Almost surely, 2^13781116449 is an apocalyptic number.

13781116449 is the 117393-rd square number.

13781116449 is the 58697-th centered octagonal number.

It is an amenable number.

13781116449 is a deficient number, since it is larger than the sum of its proper divisors (6365358354).

13781116449 is an frugal number, since it uses more digits than its factorization.

13781116449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 942 (or 471 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The spelling of 13781116449 in words is "thirteen billion, seven hundred eighty-one million, one hundred sixteen thousand, four hundred forty-nine".