381992391 has 12 divisors (see below), whose sum is σ = 601927560. Its totient is φ = 231510480.

The previous prime is 381992389. The next prime is 381992407. The reversal of 381992391 is 193299183.

It is a happy number.

It is not a de Polignac number, because 381992391 - 2¹ = 381992389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381992791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1929156 + ... + 1929353.

It is an arithmetic number, because the mean of its divisors is an integer number (50160630).

Almost surely, 2^381992391 is an apocalyptic number.

381992391 is a deficient number, since it is larger than the sum of its proper divisors (219935169).

381992391 is a wasteful number, since it uses less digits than its factorization.

381992391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3858526 (or 3858523 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 381992391 is about 19544.6256295689. The cubic root of 381992391 is about 725.5793330589.

The spelling of 381992391 in words is "three hundred eighty-one million, nine hundred ninety-two thousand, three hundred ninety-one".