691861795715 has 4 divisors (see below), whose sum is σ = 830234154864. Its totient is φ = 553489436568.

The previous prime is 691861795631. The next prime is 691861795717. The reversal of 691861795715 is 517597168196.

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 691861795715 - 2⁸ = 691861795459 is a prime.

It is a super-2 number, since 2×691861795715² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691861795717) 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, 69186179567 + ... + 69186179576.

It is an arithmetic number, because the mean of its divisors is an integer number (207558538716).

Almost surely, 2^691861795715 is an apocalyptic number.

691861795715 is a deficient number, since it is larger than the sum of its proper divisors (138372359149).

691861795715 is a wasteful number, since it uses less digits than its factorization.

691861795715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138372359148.

The product of its digits is 28576800, while the sum is 65.

The spelling of 691861795715 in words is "six hundred ninety-one billion, eight hundred sixty-one million, seven hundred ninety-five thousand, seven hundred fifteen".