6649781275 has 18 divisors (see below), whose sum is σ = 8619843260. Its totient is φ = 5088518160.

The previous prime is 6649781273. The next prime is 6649781293. The reversal of 6649781275 is 5721879466.

It is not a de Polignac number, because 6649781275 - 2¹ = 6649781273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6649781273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 238185 + ... + 264634.

Almost surely, 2^6649781275 is an apocalyptic number.

6649781275 is a deficient number, since it is larger than the sum of its proper divisors (1970061985).

6649781275 is a wasteful number, since it uses less digits than its factorization.

6649781275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502875 (or 502847 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 55.

The square root of 6649781275 is about 81546.1910514526. The cubic root of 6649781275 is about 1880.4817381549.

The spelling of 6649781275 in words is "six billion, six hundred forty-nine million, seven hundred eighty-one thousand, two hundred seventy-five".