6394737861 has 20 divisors (see below), whose sum is σ = 9810816972. Its totient is φ = 4147936128.

The previous prime is 6394737857. The next prime is 6394737893. The reversal of 6394737861 is 1687374936.

It can be written as a sum of positive squares in 2 ways, for example, as 4628216961 + 1766520900 = 68031^2 + 42030^2 .

It is not a de Polignac number, because 6394737861 - 2² = 6394737857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6394737798 and 6394737807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6394737841) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1063860 + ... + 1069853.

Almost surely, 2^6394737861 is an apocalyptic number.

It is an amenable number.

6394737861 is a deficient number, since it is larger than the sum of its proper divisors (3416079111).

6394737861 is a wasteful number, since it uses less digits than its factorization.

6394737861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2133762 (or 2133753 counting only the distinct ones).

The product of its digits is 4572288, while the sum is 54.

The square root of 6394737861 is about 79967.1048681894. The cubic root of 6394737861 is about 1856.1265463045.

The spelling of 6394737861 in words is "six billion, three hundred ninety-four million, seven hundred thirty-seven thousand, eight hundred sixty-one".