393999791653 has 6 divisors (see below), whose sum is σ = 424309905222. Its totient is φ = 363690026280.

The previous prime is 393999791617. The next prime is 393999791657. The reversal of 393999791653 is 356197999393.

It can be written as a sum of positive squares in only one way, i.e., 272769086529 + 121230705124 = 522273^2 + 348182^2 .

It is not a de Polignac number, because 393999791653 - 2²⁵ = 393966237221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393999791657) 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 5 ways as a sum of consecutive naturals, for example, 2176138 + ... + 2350228.

It is an arithmetic number, because the mean of its divisors is an integer number (70718317537).

Almost surely, 2^393999791653 is an apocalyptic number.

It is an amenable number.

393999791653 is a deficient number, since it is larger than the sum of its proper divisors (30310113569).

393999791653 is an frugal number, since it uses more digits than its factorization.

393999791653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348195 (or 174104 counting only the distinct ones).

The product of its digits is 334807830, while the sum is 73.

The spelling of 393999791653 in words is "three hundred ninety-three billion, nine hundred ninety-nine million, seven hundred ninety-one thousand, six hundred fifty-three".