7878558787 has 4 divisors (see below), whose sum is σ = 8594791416. Its totient is φ = 7162326160.

The previous prime is 7878558773. The next prime is 7878558797.

7878558787 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 7878558787 - 2¹⁹ = 7878034499 is a prime.

It is a super-2 number, since 2×7878558787² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7878558707) 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, 358116298 + ... + 358116319.

It is an arithmetic number, because the mean of its divisors is an integer number (2148697854).

Almost surely, 2^7878558787 is an apocalyptic number.

7878558787 is a deficient number, since it is larger than the sum of its proper divisors (716232629).

7878558787 is a wasteful number, since it uses less digits than its factorization.

7878558787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716232628.

The product of its digits is 245862400, while the sum is 70.

The square root of 7878558787 is about 88761.2459748059. The cubic root of 7878558787 is about 1989.8282544137.

It can be divided in two parts, 7878 and 558787, that added together give a palindrome (566665).

The spelling of 7878558787 in words is "seven billion, eight hundred seventy-eight million, five hundred fifty-eight thousand, seven hundred eighty-seven".