381887999 has 4 divisors (see below), whose sum is σ = 388148520. Its totient is φ = 375627480.

The previous prime is 381887993. The next prime is 381888107. The reversal of 381887999 is 999788183.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 381887999 - 2⁸ = 381887743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381887993) 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, 3130169 + ... + 3130290.

It is an arithmetic number, because the mean of its divisors is an integer number (97037130).

Almost surely, 2^381887999 is an apocalyptic number.

381887999 is a deficient number, since it is larger than the sum of its proper divisors (6260521).

381887999 is an equidigital number, since it uses as much as digits as its factorization.

381887999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6260520.

The product of its digits is 7838208, while the sum is 62.

The square root of 381887999 is about 19541.9548408034. The cubic root of 381887999 is about 725.5132308882.

The spelling of 381887999 in words is "three hundred eighty-one million, eight hundred eighty-seven thousand, nine hundred ninety-nine".