2638973809 has 2 divisors, whose sum is σ = 2638973810. Its totient is φ = 2638973808.

The previous prime is 2638973807. The next prime is 2638973819. The reversal of 2638973809 is 9083798362.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2605796209 + 33177600 = 51047^2 + 5760^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638973809 - 2¹ = 2638973807 is a prime.

Together with 2638973807, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2638973809.

It is not a weakly prime, because it can be changed into another prime (2638973807) 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 as a sum of consecutive naturals, namely, 1319486904 + 1319486905.

It is an arithmetic number, because the mean of its divisors is an integer number (1319486905).

Almost surely, 2^2638973809 is an apocalyptic number.

It is an amenable number.

2638973809 is a deficient number, since it is larger than the sum of its proper divisors (1).

2638973809 is an equidigital number, since it uses as much as digits as its factorization.

2638973809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3919104, while the sum is 55.

The square root of 2638973809 is about 51370.9432364250. The cubic root of 2638973809 is about 1381.9055466801.

The spelling of 2638973809 in words is "two billion, six hundred thirty-eight million, nine hundred seventy-three thousand, eight hundred nine".