381087891 has 12 divisors (see below), whose sum is σ = 562172832. Its totient is φ = 248652816.

The previous prime is 381087881. The next prime is 381087899. The reversal of 381087891 is 198780183.

It is not a de Polignac number, because 381087891 - 2⁵ = 381087859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (381087899) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 450036 + ... + 450881.

It is an arithmetic number, because the mean of its divisors is an integer number (46847736).

Almost surely, 2^381087891 is an apocalyptic number.

381087891 is a deficient number, since it is larger than the sum of its proper divisors (181084941).

381087891 is a wasteful number, since it uses less digits than its factorization.

381087891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900970 (or 900967 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The square root of 381087891 is about 19521.4725622838. The cubic root of 381087891 is about 725.0061932091.

The spelling of 381087891 in words is "three hundred eighty-one million, eighty-seven thousand, eight hundred ninety-one".