649690 has 8 divisors (see below), whose sum is σ = 1169460. Its totient is φ = 259872.

The previous prime is 649661. The next prime is 649697. The reversal of 649690 is 96946.

It can be written as a sum of positive squares in 2 ways, for example, as 606841 + 42849 = 779^2 + 207^2 .

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

It is a super-2 number, since 2×649690² = 844194192200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (649697) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32475 + ... + 32494.

2⁶⁴⁹⁶⁹⁰ is an apocalyptic number.

649690 is a deficient number, since it is larger than the sum of its proper divisors (519770).

649690 is a wasteful number, since it uses less digits than its factorization.

649690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64976.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 649690 is about 806.0334980632. The cubic root of 649690 is about 86.6101373636.

The spelling of 649690 in words is "six hundred forty-nine thousand, six hundred ninety".