2638728247 has 4 divisors (see below), whose sum is σ = 2639182816. Its totient is φ = 2638273680.

The previous prime is 2638728203. The next prime is 2638728289. The reversal of 2638728247 is 7428278362.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7428278362 = 2 ⋅3714139181.

It is a cyclic number.

It is not a de Polignac number, because 2638728247 - 2¹⁹ = 2638203959 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2638728247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638725247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218463 + ... + 230224.

It is an arithmetic number, because the mean of its divisors is an integer number (659795704).

Almost surely, 2^2638728247 is an apocalyptic number.

2638728247 is a deficient number, since it is larger than the sum of its proper divisors (454569).

2638728247 is an equidigital number, since it uses as much as digits as its factorization.

2638728247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454568.

The product of its digits is 1806336, while the sum is 49.

The square root of 2638728247 is about 51368.5530942813. The cubic root of 2638728247 is about 1381.8626822891.

The spelling of 2638728247 in words is "two billion, six hundred thirty-eight million, seven hundred twenty-eight thousand, two hundred forty-seven".