654905 has 4 divisors (see below), whose sum is σ = 785892. Its totient is φ = 523920.

The previous prime is 654889. The next prime is 654917. The reversal of 654905 is 509456.

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

It can be written as a sum of positive squares in 2 ways, for example, as 89401 + 565504 = 299^2 + 752^2 .

It is not a de Polignac number, because 654905 - 2⁴ = 654889 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 65486 + ... + 65495.

It is an arithmetic number, because the mean of its divisors is an integer number (196473).

2⁶⁵⁴⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

654905 is a deficient number, since it is larger than the sum of its proper divisors (130987).

654905 is a wasteful number, since it uses less digits than its factorization.

654905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130986.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 654905 is about 809.2620094877. The cubic root of 654905 is about 86.8412571889.

The spelling of 654905 in words is "six hundred fifty-four thousand, nine hundred five".