649637 has 4 divisors (see below), whose sum is σ = 655500. Its totient is φ = 643776.

The previous prime is 649633. The next prime is 649639. The reversal of 649637 is 736946.

It is a Cunningham number, because it is equal to 806²+1.

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 11236 + 638401 = 106^2 + 799^2 .

It is a cyclic number.

It is not a de Polignac number, because 649637 - 2² = 649633 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 649597 and 649606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649631) 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, 2762 + ... + 2987.

It is an arithmetic number, because the mean of its divisors is an integer number (163875).

2⁶⁴⁹⁶³⁷ is an apocalyptic number.

It is an amenable number.

649637 is a deficient number, since it is larger than the sum of its proper divisors (5863).

649637 is a wasteful number, since it uses less digits than its factorization.

649637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5862.

The product of its digits is 27216, while the sum is 35.

The square root of 649637 is about 806.0006203472. Note that the first 3 decimals coincide. The cubic root of 649637 is about 86.6077821572.

The spelling of 649637 in words is "six hundred forty-nine thousand, six hundred thirty-seven".