391057287 has 8 divisors (see below), whose sum is σ = 526283136. Its totient is φ = 258268152.

The previous prime is 391057253. The next prime is 391057291. The reversal of 391057287 is 782750193.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 391057287 - 2¹⁹ = 390532999 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391057207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 608803 + ... + 609444.

It is an arithmetic number, because the mean of its divisors is an integer number (65785392).

Almost surely, 2^391057287 is an apocalyptic number.

391057287 is a deficient number, since it is larger than the sum of its proper divisors (135225849).

391057287 is a wasteful number, since it uses less digits than its factorization.

391057287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1218357.

The product of its (nonzero) digits is 105840, while the sum is 42.

The square root of 391057287 is about 19775.1684442889. The cubic root of 391057287 is about 731.2739916447.

The spelling of 391057287 in words is "three hundred ninety-one million, fifty-seven thousand, two hundred eighty-seven".