6646657281 has 16 divisors (see below), whose sum is σ = 9725764608. Its totient is φ = 4004152400.

The previous prime is 6646657279. The next prime is 6646657289. The reversal of 6646657281 is 1827566466.

It is a cyclic number.

It is not a de Polignac number, because 6646657281 - 2¹ = 6646657279 is a prime.

It is a super-2 number, since 2×6646657281² = 88356106022140625922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6646657289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 597525 + ... + 608546.

It is an arithmetic number, because the mean of its divisors is an integer number (607860288).

Almost surely, 2^6646657281 is an apocalyptic number.

It is an amenable number.

6646657281 is a deficient number, since it is larger than the sum of its proper divisors (3079107327).

6646657281 is a wasteful number, since it uses less digits than its factorization.

6646657281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206252.

The product of its digits is 2903040, while the sum is 51.

The square root of 6646657281 is about 81527.0340500622. The cubic root of 6646657281 is about 1880.1872154928.

The spelling of 6646657281 in words is "six billion, six hundred forty-six million, six hundred fifty-seven thousand, two hundred eighty-one".