649502681 has 8 divisors (see below), whose sum is σ = 687027840. Its totient is φ = 612751392.

The previous prime is 649502671. The next prime is 649502701. The reversal of 649502681 is 186205946.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 649502681 - 2⁶ = 649502617 is a prime.

It is a super-2 number, since 2×649502681² = 843707465252375522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (649502641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191741 + ... + 195098.

It is an arithmetic number, because the mean of its divisors is an integer number (85878480).

Almost surely, 2^649502681 is an apocalyptic number.

It is an amenable number.

649502681 is a deficient number, since it is larger than the sum of its proper divisors (37525159).

649502681 is a wasteful number, since it uses less digits than its factorization.

649502681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386935.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 649502681 is about 25485.3424736651. The cubic root of 649502681 is about 866.0181273507.

The spelling of 649502681 in words is "six hundred forty-nine million, five hundred two thousand, six hundred eighty-one".