78085505551 has 4 divisors (see below), whose sum is σ = 78086290312. Its totient is φ = 78084720792.

The previous prime is 78085505543. The next prime is 78085505557. The reversal of 78085505551 is 15550558087.

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 a cyclic number.

It is not a de Polignac number, because 78085505551 - 2³ = 78085505543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78085505495 and 78085505504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78085505557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 216996 + ... + 450841.

It is an arithmetic number, because the mean of its divisors is an integer number (19521572578).

Almost surely, 2^78085505551 is an apocalyptic number.

78085505551 is a deficient number, since it is larger than the sum of its proper divisors (784761).

78085505551 is a wasteful number, since it uses less digits than its factorization.

78085505551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784760.

The product of its (nonzero) digits is 1400000, while the sum is 49.

The spelling of 78085505551 in words is "seventy-eight billion, eighty-five million, five hundred five thousand, five hundred fifty-one".