391623 has 8 divisors (see below), whose sum is σ = 539136. Its totient is φ = 252600.

The previous prime is 391619. The next prime is 391627. The reversal of 391623 is 326193.

It is an interprime number because it is at equal distance from previous prime (391619) and next prime (391627).

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

It is not a de Polignac number, because 391623 - 2² = 391619 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 391593 and 391602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391627) 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 7 ways as a sum of consecutive naturals, for example, 2013 + ... + 2198.

It is an arithmetic number, because the mean of its divisors is an integer number (67392).

2³⁹¹⁶²³ is an apocalyptic number.

391623 is a deficient number, since it is larger than the sum of its proper divisors (147513).

391623 is a wasteful number, since it uses less digits than its factorization.

391623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4245.

The product of its digits is 972, while the sum is 24.

The square root of 391623 is about 625.7978906963. The cubic root of 391623 is about 73.1626448000.

The spelling of 391623 in words is "three hundred ninety-one thousand, six hundred twenty-three".