381636549 has 72 divisors (see below), whose sum is σ = 683142720. Its totient is φ = 210558096.

The previous prime is 381636533. The next prime is 381636551. The reversal of 381636549 is 945636183.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

381636549 is a `hidden beast` number, since 3 + 8 + 1 + 636 + 5 + 4 + 9 = 666.

It is not a de Polignac number, because 381636549 - 2⁴ = 381636533 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381636589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 13159867 + ... + 13159895.

Almost surely, 2^381636549 is an apocalyptic number.

It is an amenable number.

381636549 is a deficient number, since it is larger than the sum of its proper divisors (301506171).

381636549 is an frugal number, since it uses more digits than its factorization.

381636549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 39 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 381636549 is about 19535.5201875967. The cubic root of 381636549 is about 725.3539604941.

The spelling of 381636549 in words is "three hundred eighty-one million, six hundred thirty-six thousand, five hundred forty-nine".