649521 has 6 divisors (see below), whose sum is σ = 938210. Its totient is φ = 433008.

The previous prime is 649511. The next prime is 649529. The reversal of 649521 is 125946.

649521 is nontrivially palindromic in base 7.

649521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 404496 + 245025 = 636^2 + 495^2 .

It is not a de Polignac number, because 649521 - 2⁶ = 649457 is a prime.

It is a Duffinian number.

649521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (649529) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36076 + ... + 36093.

2⁶⁴⁹⁵²¹ is an apocalyptic number.

It is an amenable number.

649521 is a deficient number, since it is larger than the sum of its proper divisors (288689).

649521 is a wasteful number, since it uses less digits than its factorization.

649521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72175 (or 72172 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 649521 is about 805.9286568922. The cubic root of 649521 is about 86.6026269189.

The spelling of 649521 in words is "six hundred forty-nine thousand, five hundred twenty-one".