78696551 has 4 divisors (see below), whose sum is σ = 78818832. Its totient is φ = 78574272.

The previous prime is 78696509. The next prime is 78696571. The reversal of 78696551 is 15569687.

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

It is a cyclic number.

It is not a de Polignac number, because 78696551 - 2⁶ = 78696487 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78696496 and 78696505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78696571) 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, 60170 + ... + 61463.

It is an arithmetic number, because the mean of its divisors is an integer number (19704708).

Almost surely, 2^78696551 is an apocalyptic number.

78696551 is a deficient number, since it is larger than the sum of its proper divisors (122281).

78696551 is a wasteful number, since it uses less digits than its factorization.

78696551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122280.

The product of its digits is 453600, while the sum is 47.

The square root of 78696551 is about 8871.1076535008. The cubic root of 78696551 is about 428.5339490663.

The spelling of 78696551 in words is "seventy-eight million, six hundred ninety-six thousand, five hundred fifty-one".