691006091 has 4 divisors (see below), whose sum is σ = 697714992. Its totient is φ = 684297192.

The previous prime is 691006073. The next prime is 691006093. The reversal of 691006091 is 190600196.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 691006091 - 2¹⁰ = 691005067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691006093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3354296 + ... + 3354501.

It is an arithmetic number, because the mean of its divisors is an integer number (174428748).

Almost surely, 2^691006091 is an apocalyptic number.

691006091 is a deficient number, since it is larger than the sum of its proper divisors (6708901).

691006091 is a wasteful number, since it uses less digits than its factorization.

691006091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6708900.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 691006091 is about 26286.9947122146. The cubic root of 691006091 is about 884.0848705907.

The spelling of 691006091 in words is "six hundred ninety-one million, six thousand, ninety-one".