387138809 has 4 divisors (see below), whose sum is σ = 391803216. Its totient is φ = 382474404.

The previous prime is 387138781. The next prime is 387138811. The reversal of 387138809 is 908831783.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 387138809 - 2²⁰ = 386090233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (387138109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2332079 + ... + 2332244.

It is an arithmetic number, because the mean of its divisors is an integer number (97950804).

Almost surely, 2^387138809 is an apocalyptic number.

It is an amenable number.

387138809 is a deficient number, since it is larger than the sum of its proper divisors (4664407).

387138809 is an equidigital number, since it uses as much as digits as its factorization.

387138809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4664406.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 387138809 is about 19675.8432856129. The cubic root of 387138809 is about 728.8232802925.

The spelling of 387138809 in words is "three hundred eighty-seven million, one hundred thirty-eight thousand, eight hundred nine".