381866906 has 4 divisors (see below), whose sum is σ = 572800362. Its totient is φ = 190933452.

The previous prime is 381866857. The next prime is 381866909. The reversal of 381866906 is 609668183.

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

It can be written as a sum of positive squares in only one way, i.e., 275261281 + 106605625 = 16591^2 + 10325^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (381866909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95466725 + ... + 95466728.

Almost surely, 2^381866906 is an apocalyptic number.

381866906 is a deficient number, since it is larger than the sum of its proper divisors (190933456).

381866906 is a wasteful number, since it uses less digits than its factorization.

381866906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190933455.

The product of its (nonzero) digits is 373248, while the sum is 47.

The square root of 381866906 is about 19541.4151483458. The cubic root of 381866906 is about 725.4998731041.

The spelling of 381866906 in words is "three hundred eighty-one million, eight hundred sixty-six thousand, nine hundred six".