394722721 has 8 divisors (see below), whose sum is σ = 408441600. Its totient is φ = 381065520.

The previous prime is 394722707. The next prime is 394722733. The reversal of 394722721 is 127227493.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 394722721 - 2⁵ = 394722689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394722751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2206 + ... + 28183.

It is an arithmetic number, because the mean of its divisors is an integer number (51055200).

Almost surely, 2^394722721 is an apocalyptic number.

394722721 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

394722721 is a deficient number, since it is larger than the sum of its proper divisors (13718879).

394722721 is a wasteful number, since it uses less digits than its factorization.

394722721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30839.

The product of its digits is 42336, while the sum is 37.

The square root of 394722721 is about 19867.6299794414. The cubic root of 394722721 is about 733.5516674732.

The spelling of 394722721 in words is "three hundred ninety-four million, seven hundred twenty-two thousand, seven hundred twenty-one".