394872735321 has 15 divisors (see below), whose sum is σ = 589880065423. Its totient is φ = 263244719880.

The previous prime is 394872735319. The next prime is 394872735329. The reversal of 394872735321 is 123537278493.

It is a happy number.

The square root of 394872735321 is 628389.

It is a perfect power (a square), and thus also a powerful number.

394872735321 is a `hidden beast` number, since 3 + 9 + 4 + 87 + 27 + 3 + 532 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 38392091721 + 356480643600 = 195939^2 + 597060^2 .

It is not a de Polignac number, because 394872735321 - 2¹ = 394872735319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394872735329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 5620591 + ... + 5690411.

Almost surely, 2^394872735321 is an apocalyptic number.

394872735321 is the 628389-th square number.

394872735321 is the 314195-th centered octagonal number.

It is an amenable number.

394872735321 is a deficient number, since it is larger than the sum of its proper divisors (195007330102).

394872735321 is an frugal number, since it uses more digits than its factorization.

394872735321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139654 (or 69824 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 54.

The spelling of 394872735321 in words is "three hundred ninety-four billion, eight hundred seventy-two million, seven hundred thirty-five thousand, three hundred twenty-one".