691506840858 has 16 divisors (see below), whose sum is σ = 1385830416096. Its totient is φ = 230032824560.

The previous prime is 691506840823. The next prime is 691506840863. The reversal of 691506840858 is 858048605196.

It is a super-2 number, since 2×691506840858² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117360741 + ... + 117366632.

It is an arithmetic number, because the mean of its divisors is an integer number (86614401006).

Almost surely, 2^691506840858 is an apocalyptic number.

691506840858 is an abundant number, since it is smaller than the sum of its proper divisors (694323575238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691506840858 is a wasteful number, since it uses less digits than its factorization.

691506840858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234727869.

The product of its (nonzero) digits is 16588800, while the sum is 60.

The spelling of 691506840858 in words is "six hundred ninety-one billion, five hundred six million, eight hundred forty thousand, eight hundred fifty-eight".