501649 has 4 divisors (see below), whose sum is σ = 504036. Its totient is φ = 499264.

The previous prime is 501637. The next prime is 501659. The reversal of 501649 is 946105.

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 66049 + 435600 = 257^2 + 660^2 .

It is a cyclic number.

It is not a de Polignac number, because 501649 - 2⁵ = 501617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (501659) 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 3 ways as a sum of consecutive naturals, for example, 844 + ... + 1309.

It is an arithmetic number, because the mean of its divisors is an integer number (126009).

2⁵⁰¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

501649 is a deficient number, since it is larger than the sum of its proper divisors (2387).

501649 is a wasteful number, since it uses less digits than its factorization.

501649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2386.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 501649 is about 708.2718404681. The cubic root of 501649 is about 79.4572109969.

The spelling of 501649 in words is "five hundred one thousand, six hundred forty-nine".