2640138889 has 4 divisors (see below), whose sum is σ = 2666278980. Its totient is φ = 2613998800.

The previous prime is 2640138887. The next prime is 2640138899. The reversal of 2640138889 is 9888310462.

2640138889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2594170489 + 45968400 = 50933^2 + 6780^2 .

It is a cyclic number.

It is not a de Polignac number, because 2640138889 - 2¹ = 2640138887 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2640138883) 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, 13069894 + ... + 13070095.

It is an arithmetic number, because the mean of its divisors is an integer number (666569745).

Almost surely, 2^2640138889 is an apocalyptic number.

It is an amenable number.

2640138889 is a deficient number, since it is larger than the sum of its proper divisors (26140091).

2640138889 is a wasteful number, since it uses less digits than its factorization.

2640138889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26140090.

The product of its (nonzero) digits is 663552, while the sum is 49.

The square root of 2640138889 is about 51382.2818586329. The cubic root of 2640138889 is about 1382.1088824907.

The spelling of 2640138889 in words is "two billion, six hundred forty million, one hundred thirty-eight thousand, eight hundred eighty-nine".