27708447397 has 4 divisors (see below), whose sum is σ = 27708787180. Its totient is φ = 27708107616.

The previous prime is 27708447379. The next prime is 27708447413. The reversal of 27708447397 is 79374480772.

It is a happy 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 2 ways, for example, as 24726304516 + 2982142881 = 157246^2 + 54609^2 .

It is a 3-Lehmer number, since φ(27708447397) divides (27708447397-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27708447397 is a prime.

It is a super-5 number, since 5×27708447397⁵ (a number of 53 digits) contains 55555 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27708447337) 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 3 ways as a sum of consecutive naturals, for example, 33979 + ... + 237847.

It is an arithmetic number, because the mean of its divisors is an integer number (6927196795).

It is a Poulet number, since it divides 2^27708447396-1.

Almost surely, 2^27708447397 is an apocalyptic number.

27708447397 is the 135913-rd pentagonal number.

It is an amenable number.

27708447397 is a deficient number, since it is larger than the sum of its proper divisors (339783).

27708447397 is a wasteful number, since it uses less digits than its factorization.

27708447397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339782.

The product of its (nonzero) digits is 16595712, while the sum is 58.

The spelling of 27708447397 in words is "twenty-seven billion, seven hundred eight million, four hundred forty-seven thousand, three hundred ninety-seven".