6640015220 has 12 divisors (see below), whose sum is σ = 13944032004. Its totient is φ = 2656006080.

The previous prime is 6640015183. The next prime is 6640015241. The reversal of 6640015220 is 225100466.

It can be written as a sum of positive squares in 2 ways, for example, as 2455995364 + 4184019856 = 49558^2 + 64684^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 6640015220.

It is a congruent number.

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, 166000361 + ... + 166000400.

It is an arithmetic number, because the mean of its divisors is an integer number (1162002667).

Almost surely, 2^6640015220 is an apocalyptic number.

It is an amenable number.

6640015220 is an abundant number, since it is smaller than the sum of its proper divisors (7304016784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6640015220 is a wasteful number, since it uses less digits than its factorization.

6640015220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332000770 (or 332000768 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 6640015220 is about 81486.2885398519. The cubic root of 6640015220 is about 1879.5607110785.

Adding to 6640015220 its reverse (225100466), we get a palindrome (6865115686).

The spelling of 6640015220 in words is "six billion, six hundred forty million, fifteen thousand, two hundred twenty".