387791986 has 4 divisors (see below), whose sum is σ = 581687982. Its totient is φ = 193895992.

The previous prime is 387791977. The next prime is 387791993. The reversal of 387791986 is 689197783.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689197783 = 23 ⋅29965121.

It can be written as a sum of positive squares in only one way, i.e., 296493961 + 91298025 = 17219^2 + 9555^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 387791986.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96947995 + ... + 96947998.

Almost surely, 2^387791986 is an apocalyptic number.

387791986 is a deficient number, since it is larger than the sum of its proper divisors (193895996).

387791986 is a wasteful number, since it uses less digits than its factorization.

387791986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193895995.

The product of its digits is 4572288, while the sum is 58.

The square root of 387791986 is about 19692.4347402753. The cubic root of 387791986 is about 729.2329379433.

The spelling of 387791986 in words is "three hundred eighty-seven million, seven hundred ninety-one thousand, nine hundred eighty-six".