649605218 has 8 divisors (see below), whose sum is σ = 974979180. Its totient is φ = 324612160.

The previous prime is 649605181. The next prime is 649605223. The reversal of 649605218 is 812506946.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 580665409 + 68939809 = 24097^2 + 8303^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90923 + ... + 97806.

Almost surely, 2^649605218 is an apocalyptic number.

649605218 is a deficient number, since it is larger than the sum of its proper divisors (325373962).

649605218 is a wasteful number, since it uses less digits than its factorization.

649605218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190452.

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

The square root of 649605218 is about 25487.3540800139. The cubic root of 649605218 is about 866.0636977185.

The spelling of 649605218 in words is "six hundred forty-nine million, six hundred five thousand, two hundred eighteen".