6781691357638 has 16 divisors (see below), whose sum is σ = 10339775337024. Its totient is φ = 3335104690560.

The previous prime is 6781691357579. The next prime is 6781691357647. The reversal of 6781691357638 is 8367531961876.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1409331 + ... + 3943297.

It is an arithmetic number, because the mean of its divisors is an integer number (646235958564).

Almost surely, 2^{6781691357638} is an apocalyptic number.

6781691357638 is a deficient number, since it is larger than the sum of its proper divisors (3558083979386).

6781691357638 is a wasteful number, since it uses less digits than its factorization.

6781691357638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2555967.

The product of its digits is 274337280, while the sum is 70.

The spelling of 6781691357638 in words is "six trillion, seven hundred eighty-one billion, six hundred ninety-one million, three hundred fifty-seven thousand, six hundred thirty-eight".