649289768 has 8 divisors (see below), whose sum is σ = 1217418330. Its totient is φ = 324644880.

The previous prime is 649289759. The next prime is 649289779. The reversal of 649289768 is 867982946.

It can be written as a sum of positive squares in only one way, i.e., 525234724 + 124055044 = 22918^2 + 11138^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40580603 + ... + 40580618.

Almost surely, 2^649289768 is an apocalyptic number.

It is an amenable number.

649289768 is a deficient number, since it is larger than the sum of its proper divisors (568128562).

649289768 is a wasteful number, since it uses less digits than its factorization.

649289768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81161227 (or 81161223 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 59.

The square root of 649289768 is about 25481.1649655191. The cubic root of 649289768 is about 865.9234874185.

The spelling of 649289768 in words is "six hundred forty-nine million, two hundred eighty-nine thousand, seven hundred sixty-eight".