394015313081 has 4 divisors (see below), whose sum is σ = 424324183332. Its totient is φ = 363706442832.

The previous prime is 394015313077. The next prime is 394015313099. The reversal of 394015313081 is 180313510493.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 180313510493 = 62563 ⋅2882111.

It can be written as a sum of positive squares in 2 ways, for example, as 63917952400 + 330097360681 = 252820^2 + 574541^2 .

It is a cyclic number.

It is not a de Polignac number, because 394015313081 - 2² = 394015313077 is a prime.

It is a super-2 number, since 2×394015313081² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394015313981) 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, 15154435106 + ... + 15154435131.

It is an arithmetic number, because the mean of its divisors is an integer number (106081045833).

Almost surely, 2^394015313081 is an apocalyptic number.

It is an amenable number.

394015313081 is a deficient number, since it is larger than the sum of its proper divisors (30308870251).

394015313081 is a wasteful number, since it uses less digits than its factorization.

394015313081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30308870250.

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 394015313081 in words is "three hundred ninety-four billion, fifteen million, three hundred thirteen thousand, eighty-one".