691396666693195 has 8 divisors (see below), whose sum is σ = 829720647186336. Its totient is φ = 553087568584896.

The previous prime is 691396666693193. The next prime is 691396666693217. The reversal of 691396666693195 is 591396666693196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691396666693195 - 2¹ = 691396666693193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691396666693193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3720494002 + ... + 3720679831.

It is an arithmetic number, because the mean of its divisors is an integer number (103715080898292).

Almost surely, 2^{691396666693195} is an apocalyptic number.

691396666693195 is a deficient number, since it is larger than the sum of its proper divisors (138323980493141).

691396666693195 is a wasteful number, since it uses less digits than its factorization.

691396666693195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7441192421.

The product of its digits is 13774950720, while the sum is 85.

Subtracting from 691396666693195 its reverse (591396666693196), we obtain a palindrome (99999999999999).

The spelling of 691396666693195 in words is "six hundred ninety-one trillion, three hundred ninety-six billion, six hundred sixty-six million, six hundred ninety-three thousand, one hundred ninety-five".