380128709 has 4 divisors (see below), whose sum is σ = 380171616. Its totient is φ = 380085804.

The previous prime is 380128703. The next prime is 380128711. The reversal of 380128709 is 907821083.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-380128709 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (380128703) 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, 2699 + ... + 27704.

It is an arithmetic number, because the mean of its divisors is an integer number (95042904).

Almost surely, 2^380128709 is an apocalyptic number.

It is an amenable number.

380128709 is a deficient number, since it is larger than the sum of its proper divisors (42907).

380128709 is a wasteful number, since it uses less digits than its factorization.

380128709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42906.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 380128709 is about 19496.8897263128. The cubic root of 380128709 is about 724.3974122554.

The spelling of 380128709 in words is "three hundred eighty million, one hundred twenty-eight thousand, seven hundred nine".