8657861978 has 16 divisors (see below), whose sum is σ = 13173109056. Its totient is φ = 4266857280.

The previous prime is 8657861969. The next prime is 8657861999. The reversal of 8657861978 is 8791687568.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 965825 + ... + 974747.

It is an arithmetic number, because the mean of its divisors is an integer number (823319316).

Almost surely, 2^8657861978 is an apocalyptic number.

8657861978 is a deficient number, since it is larger than the sum of its proper divisors (4515247078).

8657861978 is a wasteful number, since it uses less digits than its factorization.

8657861978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15829.

The product of its digits is 40642560, while the sum is 65.

The square root of 8657861978 is about 93047.6328446887. The cubic root of 8657861978 is about 2053.3842160455.

The spelling of 8657861978 in words is "eight billion, six hundred fifty-seven million, eight hundred sixty-one thousand, nine hundred seventy-eight".