2638678091 has 4 divisors (see below), whose sum is σ = 3015632112. Its totient is φ = 2261724072.

The previous prime is 2638678073. The next prime is 2638678093. The reversal of 2638678091 is 1908768362.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1908768362 = 2 ⋅954384181.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2638678091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2638678093) 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, 188477000 + ... + 188477013.

It is an arithmetic number, because the mean of its divisors is an integer number (753908028).

Almost surely, 2^2638678091 is an apocalyptic number.

2638678091 is a deficient number, since it is larger than the sum of its proper divisors (376954021).

2638678091 is an equidigital number, since it uses as much as digits as its factorization.

2638678091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376954020.

The product of its (nonzero) digits is 870912, while the sum is 50.

The square root of 2638678091 is about 51368.0648944458. The cubic root of 2638678091 is about 1381.8539269169.

The spelling of 2638678091 in words is "two billion, six hundred thirty-eight million, six hundred seventy-eight thousand, ninety-one".