381979509 has 4 divisors (see below), whose sum is σ = 509306016. Its totient is φ = 254653004.

The previous prime is 381979487. The next prime is 381979513. The reversal of 381979509 is 905979183.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 905979183 = 3 ⋅301993061.

It is a cyclic number.

It is not a de Polignac number, because 381979509 - 2¹¹ = 381977461 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381979519) 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, 63663249 + ... + 63663254.

It is an arithmetic number, because the mean of its divisors is an integer number (127326504).

Almost surely, 2^381979509 is an apocalyptic number.

It is an amenable number.

381979509 is a deficient number, since it is larger than the sum of its proper divisors (127326507).

381979509 is a wasteful number, since it uses less digits than its factorization.

381979509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127326506.

The product of its (nonzero) digits is 612360, while the sum is 51.

The square root of 381979509 is about 19544.2960732793. The cubic root of 381979509 is about 725.5711766853.

The spelling of 381979509 in words is "three hundred eighty-one million, nine hundred seventy-nine thousand, five hundred nine".