381631394 has 16 divisors (see below), whose sum is σ = 588965496. Its totient is φ = 185328000.

The previous prime is 381631391. The next prime is 381631409. The reversal of 381631394 is 493136183.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 333537169 + 48094225 = 18263^2 + 6935^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (381631391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40184 + ... + 48764.

Almost surely, 2^381631394 is an apocalyptic number.

381631394 is a deficient number, since it is larger than the sum of its proper divisors (207334102).

381631394 is a wasteful number, since it uses less digits than its factorization.

381631394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9221.

The product of its digits is 46656, while the sum is 38.

The square root of 381631394 is about 19535.3882479975. The cubic root of 381631394 is about 725.3506945451.

The spelling of 381631394 in words is "three hundred eighty-one million, six hundred thirty-one thousand, three hundred ninety-four".