87878779 has 4 divisors (see below), whose sum is σ = 88700184. Its totient is φ = 87057376.

The previous prime is 87878773. The next prime is 87878783. The reversal of 87878779 is 97787878.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97787878 = 2 ⋅48893939.

It is a cyclic number.

It is not a de Polignac number, because 87878779 - 2⁹ = 87878267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87878773) 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, 410542 + ... + 410755.

It is an arithmetic number, because the mean of its divisors is an integer number (22175046).

Almost surely, 2^87878779 is an apocalyptic number.

87878779 is a deficient number, since it is larger than the sum of its proper divisors (821405).

87878779 is a wasteful number, since it uses less digits than its factorization.

87878779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821404.

The product of its digits is 11063808, while the sum is 61.

The square root of 87878779 is about 9374.3681920437. The cubic root of 87878779 is about 444.5916870725.

Subtracting 87878779 from its reverse (97787878), we obtain a palindrome (9909099).

It can be divided in two parts, 8 and 7878779, that added together give a palindrome (7878787).

The spelling of 87878779 in words is "eighty-seven million, eight hundred seventy-eight thousand, seven hundred seventy-nine".