7978138185 has 8 divisors (see below), whose sum is σ = 12765021120. Its totient is φ = 4255007024.

The previous prime is 7978138169. The next prime is 7978138213. The reversal of 7978138185 is 5818318797.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7978138185 - 2⁴ = 7978138169 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 265937925 + ... + 265937954.

It is an arithmetic number, because the mean of its divisors is an integer number (1595627640).

Almost surely, 2^7978138185 is an apocalyptic number.

It is an amenable number.

7978138185 is a deficient number, since it is larger than the sum of its proper divisors (4786882935).

7978138185 is a wasteful number, since it uses less digits than its factorization.

7978138185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531875887.

The product of its digits is 3386880, while the sum is 57.

The square root of 7978138185 is about 89320.4242320870. The cubic root of 7978138185 is about 1998.1765200490.

The spelling of 7978138185 in words is "seven billion, nine hundred seventy-eight million, one hundred thirty-eight thousand, one hundred eighty-five".