380392721 has 4 divisors (see below), whose sum is σ = 382518000. Its totient is φ = 378267444.

The previous prime is 380392717. The next prime is 380392729. The reversal of 380392721 is 127293083.

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: 127293083 = 223 ⋅570821.

It is a cyclic number.

It is not a de Polignac number, because 380392721 - 2² = 380392717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (380392729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1062371 + ... + 1062728.

It is an arithmetic number, because the mean of its divisors is an integer number (95629500).

Almost surely, 2^380392721 is an apocalyptic number.

It is an amenable number.

380392721 is a deficient number, since it is larger than the sum of its proper divisors (2125279).

380392721 is a wasteful number, since it uses less digits than its factorization.

380392721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2125278.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 380392721 is about 19503.6591694995. The cubic root of 380392721 is about 724.5650794567.

The spelling of 380392721 in words is "three hundred eighty million, three hundred ninety-two thousand, seven hundred twenty-one".