393903903871 has 4 divisors (see below), whose sum is σ = 395552037600. Its totient is φ = 392255770144.

The previous prime is 393903903859. The next prime is 393903903889. The reversal of 393903903871 is 178309309393.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 393903903871 - 2²³ = 393895515263 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 (393903903851) 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, 824066506 + ... + 824066983.

It is an arithmetic number, because the mean of its divisors is an integer number (98888009400).

Almost surely, 2^393903903871 is an apocalyptic number.

393903903871 is a deficient number, since it is larger than the sum of its proper divisors (1648133729).

393903903871 is a wasteful number, since it uses less digits than its factorization.

393903903871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1648133728.

The product of its (nonzero) digits is 3306744, while the sum is 55.

The spelling of 393903903871 in words is "three hundred ninety-three billion, nine hundred three million, nine hundred three thousand, eight hundred seventy-one".