2640278217 has 16 divisors (see below), whose sum is σ = 3603840768. Its totient is φ = 1718487120.

The previous prime is 2640278203. The next prime is 2640278239. The reversal of 2640278217 is 7128720462.

It is not a de Polignac number, because 2640278217 - 2⁸ = 2640277961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2640278297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 525238 + ... + 530240.

It is an arithmetic number, because the mean of its divisors is an integer number (225240048).

Almost surely, 2^2640278217 is an apocalyptic number.

It is an amenable number.

2640278217 is a deficient number, since it is larger than the sum of its proper divisors (963562551).

2640278217 is a wasteful number, since it uses less digits than its factorization.

2640278217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9140.

The product of its (nonzero) digits is 75264, while the sum is 39.

The square root of 2640278217 is about 51383.6376388437. The cubic root of 2640278217 is about 1382.1331947317.

Adding to 2640278217 its reverse (7128720462), we get a palindrome (9768998679).

The spelling of 2640278217 in words is "two billion, six hundred forty million, two hundred seventy-eight thousand, two hundred seventeen".