6782137821 has 6 divisors (see below), whose sum is σ = 9796421310. Its totient is φ = 4521425208.

The previous prime is 6782137783. The next prime is 6782137829. The reversal of 6782137821 is 1287312876.

It can be written as a sum of positive squares in only one way, i.e., 6677177796 + 104960025 = 81714^2 + 10245^2 .

It is not a de Polignac number, because 6782137821 - 2⁹ = 6782137309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6782137829) 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, 376785426 + ... + 376785443.

It is an arithmetic number, because the mean of its divisors is an integer number (1632736885).

Almost surely, 2^6782137821 is an apocalyptic number.

It is an amenable number.

6782137821 is a deficient number, since it is larger than the sum of its proper divisors (3014283489).

6782137821 is a wasteful number, since it uses less digits than its factorization.

6782137821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753570875 (or 753570872 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 6782137821 is about 82353.7359261861. The cubic root of 6782137821 is about 1892.8761692920.

The spelling of 6782137821 in words is "six billion, seven hundred eighty-two million, one hundred thirty-seven thousand, eight hundred twenty-one".