391051 has 4 divisors (see below), whose sum is σ = 414072. Its totient is φ = 368032.

The previous prime is 391049. The next prime is 391057. The reversal of 391051 is 150193.

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 391051 - 2¹ = 391049 is a prime.

It is a Duffinian number.

391051 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (391057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11485 + ... + 11518.

It is an arithmetic number, because the mean of its divisors is an integer number (103518).

2³⁹¹⁰⁵¹ is an apocalyptic number.

391051 is the 396-th centered pentagonal number.

391051 is a deficient number, since it is larger than the sum of its proper divisors (23021).

391051 is a wasteful number, since it uses less digits than its factorization.

391051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23020.

The product of its (nonzero) digits is 135, while the sum is 19.

The square root of 391051 is about 625.3407071349. The cubic root of 391051 is about 73.1270072744.

The spelling of 391051 in words is "three hundred ninety-one thousand, fifty-one".