381878191 has 4 divisors (see below), whose sum is σ = 404341632. Its totient is φ = 359414752.

The previous prime is 381878183. The next prime is 381878201. The reversal of 381878191 is 191878183.

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 381878191 - 2³ = 381878183 is a prime.

It is a super-2 number, since 2×381878191² = 291661905522864962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381878291) 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, 11231695 + ... + 11231728.

It is an arithmetic number, because the mean of its divisors is an integer number (101085408).

Almost surely, 2^381878191 is an apocalyptic number.

381878191 is a deficient number, since it is larger than the sum of its proper divisors (22463441).

381878191 is a wasteful number, since it uses less digits than its factorization.

381878191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22463440.

The product of its digits is 96768, while the sum is 46.

The square root of 381878191 is about 19541.7038919333. The cubic root of 381878191 is about 725.5070197350.

The spelling of 381878191 in words is "three hundred eighty-one million, eight hundred seventy-eight thousand, one hundred ninety-one".