649961 has 12 divisors (see below), whose sum is σ = 747852. Its totient is φ = 561408.

The previous prime is 649937. The next prime is 649969. The reversal of 649961 is 169946.

649961 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in 6 ways, for example, as 72361 + 577600 = 269^2 + 760^2 .

It is not a de Polignac number, because 649961 - 2⁶ = 649897 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 649961.

It is not an unprimeable number, because it can be changed into a prime (649969) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3671 + ... + 3843.

It is an arithmetic number, because the mean of its divisors is an integer number (62321).

2⁶⁴⁹⁹⁶¹ is an apocalyptic number.

It is an amenable number.

649961 is a deficient number, since it is larger than the sum of its proper divisors (97891).

649961 is a wasteful number, since it uses less digits than its factorization.

649961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 203 counting only the distinct ones).

The product of its digits is 11664, while the sum is 35.

The square root of 649961 is about 806.2015876938. The cubic root of 649961 is about 86.6221780212.

The spelling of 649961 in words is "six hundred forty-nine thousand, nine hundred sixty-one".