691268988007 has 4 divisors (see below), whose sum is σ = 744443525560. Its totient is φ = 638094450456.

The previous prime is 691268987987. The next prime is 691268988017. The reversal of 691268988007 is 700889862196.

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 691268988007 - 2³⁹ = 141513174119 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 691268988007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691268988017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26587268757 + ... + 26587268782.

It is an arithmetic number, because the mean of its divisors is an integer number (186110881390).

Almost surely, 2^691268988007 is an apocalyptic number.

691268988007 is a deficient number, since it is larger than the sum of its proper divisors (53174537553).

691268988007 is a wasteful number, since it uses less digits than its factorization.

691268988007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53174537552.

The product of its (nonzero) digits is 20901888, while the sum is 64.

The spelling of 691268988007 in words is "six hundred ninety-one billion, two hundred sixty-eight million, nine hundred eighty-eight thousand, seven".