399240604391 has 4 divisors (see below), whose sum is σ = 420253267800. Its totient is φ = 378227940984.

The previous prime is 399240604379. The next prime is 399240604393. The reversal of 399240604391 is 193406042993.

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

It is not a de Polignac number, because 399240604391 - 2¹⁰ = 399240603367 is a prime.

It is a super-3 number, since 3×399240604391³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399240604393) 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, 10506331676 + ... + 10506331713.

It is an arithmetic number, because the mean of its divisors is an integer number (105063316950).

Almost surely, 2^399240604391 is an apocalyptic number.

399240604391 is a deficient number, since it is larger than the sum of its proper divisors (21012663409).

399240604391 is a wasteful number, since it uses less digits than its factorization.

399240604391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21012663408.

The product of its (nonzero) digits is 1259712, while the sum is 50.

The spelling of 399240604391 in words is "three hundred ninety-nine billion, two hundred forty million, six hundred four thousand, three hundred ninety-one".