2639817989 has 6 divisors (see below), whose sum is σ = 2727721350. Its totient is φ = 2554661640.

The previous prime is 2639817977. The next prime is 2639817997. The reversal of 2639817989 is 9897189362.

It can be written as a sum of positive squares in only one way, i.e., 2040057889 + 599760100 = 45167^2 + 24490^2 .

It is not a de Polignac number, because 2639817989 - 2¹² = 2639813893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2639817959) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1372514 + ... + 1374435.

It is an arithmetic number, because the mean of its divisors is an integer number (454620225).

Almost surely, 2^2639817989 is an apocalyptic number.

It is an amenable number.

2639817989 is a deficient number, since it is larger than the sum of its proper divisors (87903361).

2639817989 is an equidigital number, since it uses as much as digits as its factorization.

2639817989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2747011 (or 2746980 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 62.

The square root of 2639817989 is about 51379.1590919898. The cubic root of 2639817989 is about 1382.0528833268.

The spelling of 2639817989 in words is "two billion, six hundred thirty-nine million, eight hundred seventeen thousand, nine hundred eighty-nine".