1691312193385 has 4 divisors (see below), whose sum is σ = 2029574632068. Its totient is φ = 1353049754704.

The previous prime is 1691312193323. The next prime is 1691312193409. The reversal of 1691312193385 is 5833912131961.

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 755194022361 + 936118171024 = 869019^2 + 967532^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691312193385 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169131219334 + ... + 169131219343.

It is an arithmetic number, because the mean of its divisors is an integer number (507393658017).

Almost surely, 2^{1691312193385} is an apocalyptic number.

It is an amenable number.

1691312193385 is a deficient number, since it is larger than the sum of its proper divisors (338262438683).

1691312193385 is an equidigital number, since it uses as much as digits as its factorization.

1691312193385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338262438682.

The product of its digits is 1049760, while the sum is 52.

The spelling of 1691312193385 in words is "one trillion, six hundred ninety-one billion, three hundred twelve million, one hundred ninety-three thousand, three hundred eighty-five".