3864191978 has 8 divisors (see below), whose sum is σ = 5797861860. Its totient is φ = 1931571360.

The previous prime is 3864191951. The next prime is 3864191993. The reversal of 3864191978 is 8791914683.

It can be written as a sum of positive squares in 2 ways, for example, as 3111073729 + 753118249 = 55777^2 + 27443^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253043 + ... + 267878.

Almost surely, 2^3864191978 is an apocalyptic number.

3864191978 is a deficient number, since it is larger than the sum of its proper divisors (1933669882).

3864191978 is a wasteful number, since it uses less digits than its factorization.

3864191978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524632.

The product of its digits is 2612736, while the sum is 56.

The square root of 3864191978 is about 62162.6252502257. The cubic root of 3864191978 is about 1569.2286605509.

The spelling of 3864191978 in words is "three billion, eight hundred sixty-four million, one hundred ninety-one thousand, nine hundred seventy-eight".