78549480898561 has 4 divisors (see below), whose sum is σ = 78549520151124. Its totient is φ = 78549441646000.

The previous prime is 78549480898547. The next prime is 78549480898583. The reversal of 78549480898561 is 16589808494587.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62600440257936 + 15949040640625 = 7912044^2 + 3993625^2 .

It is a cyclic number.

It is not a de Polignac number, because 78549480898561 - 2¹⁹ = 78549480374273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78549480898541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16453630 + ... + 20683831.

It is an arithmetic number, because the mean of its divisors is an integer number (19637380037781).

Almost surely, 2^{78549480898561} is an apocalyptic number.

It is an amenable number.

78549480898561 is a deficient number, since it is larger than the sum of its proper divisors (39252563).

78549480898561 is a wasteful number, since it uses less digits than its factorization.

78549480898561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39252562.

The product of its (nonzero) digits is 5573836800, while the sum is 82.

The spelling of 78549480898561 in words is "seventy-eight trillion, five hundred forty-nine billion, four hundred eighty million, eight hundred ninety-eight thousand, five hundred sixty-one".