6640123225 has 24 divisors (see below), whose sum is σ = 8443006488. Its totient is φ = 5177356800.

The previous prime is 6640123201. The next prime is 6640123229. The reversal of 6640123225 is 5223210466.

It can be written as a sum of positive squares in 12 ways, for example, as 1441569024 + 5198554201 = 37968^2 + 72101^2 .

It is not a de Polignac number, because 6640123225 - 2¹¹ = 6640121177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640123229) 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 23 ways as a sum of consecutive naturals, for example, 1265307 + ... + 1270543.

It is an arithmetic number, because the mean of its divisors is an integer number (351791937).

Almost surely, 2^6640123225 is an apocalyptic number.

It is an amenable number.

6640123225 is a deficient number, since it is larger than the sum of its proper divisors (1802883263).

6640123225 is a wasteful number, since it uses less digits than its factorization.

6640123225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6525 (or 6520 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 6640123225 is about 81486.9512560140. The cubic root of 6640123225 is about 1879.5709018610.

The spelling of 6640123225 in words is "six billion, six hundred forty million, one hundred twenty-three thousand, two hundred twenty-five".