391431 has 4 divisors (see below), whose sum is σ = 521912. Its totient is φ = 260952.

The previous prime is 391403. The next prime is 391441. The reversal of 391431 is 134193.

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

It is not a de Polignac number, because 391431 - 2⁵ = 391399 is a prime.

It is a super-2 number, since 2×391431² = 306436455522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 391398 and 391407.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391431.

It is not an unprimeable number, because it can be changed into a prime (391441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65236 + ... + 65241.

It is an arithmetic number, because the mean of its divisors is an integer number (130478).

2³⁹¹⁴³¹ is an apocalyptic number.

391431 is a deficient number, since it is larger than the sum of its proper divisors (130481).

391431 is a wasteful number, since it uses less digits than its factorization.

391431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130480.

The product of its digits is 324, while the sum is 21.

The square root of 391431 is about 625.6444677291. The cubic root of 391431 is about 73.1506864250.

The spelling of 391431 in words is "three hundred ninety-one thousand, four hundred thirty-one".