691155796241 has 4 divisors (see below), whose sum is σ = 693783765312. Its totient is φ = 688527827172.

The previous prime is 691155796237. The next prime is 691155796259. The reversal of 691155796241 is 142697551196.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 691155796241 - 2² = 691155796237 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691155793241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1313984141 + ... + 1313984666.

It is an arithmetic number, because the mean of its divisors is an integer number (173445941328).

Almost surely, 2^691155796241 is an apocalyptic number.

It is an amenable number.

691155796241 is a deficient number, since it is larger than the sum of its proper divisors (2627969071).

691155796241 is a wasteful number, since it uses less digits than its factorization.

691155796241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2627969070.

The product of its digits is 4082400, while the sum is 56.

The spelling of 691155796241 in words is "six hundred ninety-one billion, one hundred fifty-five million, seven hundred ninety-six thousand, two hundred forty-one".