654721 has 8 divisors (see below), whose sum is σ = 730080. Its totient is φ = 583488.

The previous prime is 654701. The next prime is 654727. The reversal of 654721 is 127456.

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

It is a cyclic number.

It is not a de Polignac number, because 654721 - 2⁷ = 654593 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (654727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 691 + ... + 1336.

It is an arithmetic number, because the mean of its divisors is an integer number (91260).

2⁶⁵⁴⁷²¹ is an apocalyptic number.

It is an amenable number.

654721 is a deficient number, since it is larger than the sum of its proper divisors (75359).

654721 is a wasteful number, since it uses less digits than its factorization.

654721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2063.

The product of its digits is 1680, while the sum is 25.

The square root of 654721 is about 809.1483176773. The cubic root of 654721 is about 86.8331235471.

The spelling of 654721 in words is "six hundred fifty-four thousand, seven hundred twenty-one".