654691 has 4 divisors (see below), whose sum is σ = 663984. Its totient is φ = 645400.

The previous prime is 654679. The next prime is 654697. The reversal of 654691 is 196456.

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 654691 - 2¹⁵ = 621923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (654697) 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, 4540 + ... + 4681.

It is an arithmetic number, because the mean of its divisors is an integer number (165996).

2⁶⁵⁴⁶⁹¹ is an apocalyptic number.

654691 is a deficient number, since it is larger than the sum of its proper divisors (9293).

654691 is an equidigital number, since it uses as much as digits as its factorization.

654691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9292.

The product of its digits is 6480, while the sum is 31.

The square root of 654691 is about 809.1297794544. The cubic root of 654691 is about 86.8317972654.

It can be divided in two parts, 6546 and 91, that multiplied together give a triangular number (595686 = T₁₀₉₁).

The spelling of 654691 in words is "six hundred fifty-four thousand, six hundred ninety-one".