7876778578 has 4 divisors (see below), whose sum is σ = 11815167870. Its totient is φ = 3938389288.

The previous prime is 7876778573. The next prime is 7876778579. The reversal of 7876778578 is 8758776787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8758776787 = 113 ⋅77511299.

It can be written as a sum of positive squares in only one way, i.e., 7315894089 + 560884489 = 85533^2 + 23683^2 .

It is not an unprimeable number, because it can be changed into a prime (7876778573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1969194643 + ... + 1969194646.

Almost surely, 2^7876778578 is an apocalyptic number.

7876778578 is a deficient number, since it is larger than the sum of its proper divisors (3938389292).

7876778578 is a wasteful number, since it uses less digits than its factorization.

7876778578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3938389291.

The product of its digits is 258155520, while the sum is 70.

The square root of 7876778578 is about 88751.2173324963. The cubic root of 7876778578 is about 1989.6783717977.

The spelling of 7876778578 in words is "seven billion, eight hundred seventy-six million, seven hundred seventy-eight thousand, five hundred seventy-eight".