393643641 has 4 divisors (see below), whose sum is σ = 524858192. Its totient is φ = 262429092.

The previous prime is 393643639. The next prime is 393643669. The reversal of 393643641 is 146346393.

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: 146346393 = 3 ⋅48782131.

It is not a de Polignac number, because 393643641 - 2¹ = 393643639 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 393643641.

It is not an unprimeable number, because it can be changed into a prime (393643631) 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 3 ways as a sum of consecutive naturals, for example, 65607271 + ... + 65607276.

It is an arithmetic number, because the mean of its divisors is an integer number (131214548).

Almost surely, 2^393643641 is an apocalyptic number.

It is an amenable number.

393643641 is a deficient number, since it is larger than the sum of its proper divisors (131214551).

393643641 is a wasteful number, since it uses less digits than its factorization.

393643641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131214550.

The product of its digits is 139968, while the sum is 39.

The square root of 393643641 is about 19840.4546570889. The cubic root of 393643641 is about 732.8826042692.

The spelling of 393643641 in words is "three hundred ninety-three million, six hundred forty-three thousand, six hundred forty-one".