399251448791 has 4 divisors (see below), whose sum is σ = 429963098712. Its totient is φ = 368539798872.

The previous prime is 399251448727. The next prime is 399251448803. The reversal of 399251448791 is 197844152993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 197844152993 = 79 ⋅2504356367.

It is a cyclic number.

It is not a de Polignac number, because 399251448791 - 2⁶ = 399251448727 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 (399251448391) 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, 15355824941 + ... + 15355824966.

It is an arithmetic number, because the mean of its divisors is an integer number (107490774678).

Almost surely, 2^399251448791 is an apocalyptic number.

399251448791 is a deficient number, since it is larger than the sum of its proper divisors (30711649921).

399251448791 is a wasteful number, since it uses less digits than its factorization.

399251448791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30711649920.

The product of its digits is 19595520, while the sum is 62.

The spelling of 399251448791 in words is "three hundred ninety-nine billion, two hundred fifty-one million, four hundred forty-eight thousand, seven hundred ninety-one".