8138978961 has 8 divisors (see below), whose sum is σ = 10895207904. Its totient is φ = 5404368000.

The previous prime is 8138978957. The next prime is 8138978993. The reversal of 8138978961 is 1698798318.

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

It is not a de Polignac number, because 8138978961 - 2² = 8138978957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8138978895 and 8138978904.

It is not an unprimeable number, because it can be changed into a prime (8138978941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5403616 + ... + 5405121.

It is an arithmetic number, because the mean of its divisors is an integer number (1361900988).

Almost surely, 2^8138978961 is an apocalyptic number.

It is an amenable number.

8138978961 is a deficient number, since it is larger than the sum of its proper divisors (2756228943).

8138978961 is a wasteful number, since it uses less digits than its factorization.

8138978961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10808991.

The product of its digits is 5225472, while the sum is 60.

The square root of 8138978961 is about 90216.2898871373. The cubic root of 8138978961 is about 2011.5151534624.

The spelling of 8138978961 in words is "eight billion, one hundred thirty-eight million, nine hundred seventy-eight thousand, nine hundred sixty-one".