654391 has 4 divisors (see below), whose sum is σ = 666792. Its totient is φ = 641992.

The previous prime is 654371. The next prime is 654397. The reversal of 654391 is 193456.

654391 = T₆₅₉ + T₆₆₀ + T₆₆₁.

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 654391 - 2⁹ = 653879 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 (654397) 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, 6121 + ... + 6226.

It is an arithmetic number, because the mean of its divisors is an integer number (166698).

2⁶⁵⁴³⁹¹ is an apocalyptic number.

654391 is the 661-st centered triangular number.

654391 is a deficient number, since it is larger than the sum of its proper divisors (12401).

654391 is a wasteful number, since it uses less digits than its factorization.

654391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12400.

The product of its digits is 3240, while the sum is 28.

The square root of 654391 is about 808.9443738602. The cubic root of 654391 is about 86.8185322192.

The spelling of 654391 in words is "six hundred fifty-four thousand, three hundred ninety-one".