78424177261 has 4 divisors (see below), whose sum is σ = 78425754912. Its totient is φ = 78422599612.

The previous prime is 78424177253. The next prime is 78424177291. The reversal of 78424177261 is 16277142487.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78424177261 - 2³ = 78424177253 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78424177201) 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, 711751 + ... + 814516.

It is an arithmetic number, because the mean of its divisors is an integer number (19606438728).

Almost surely, 2^78424177261 is an apocalyptic number.

It is an amenable number.

78424177261 is a deficient number, since it is larger than the sum of its proper divisors (1577651).

78424177261 is a wasteful number, since it uses less digits than its factorization.

78424177261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1577650.

The product of its digits is 1053696, while the sum is 49.

The spelling of 78424177261 in words is "seventy-eight billion, four hundred twenty-four million, one hundred seventy-seven thousand, two hundred sixty-one".