689121018631 has 4 divisors (see below), whose sum is σ = 694547168512. Its totient is φ = 683694868752.

The previous prime is 689121018623. The next prime is 689121018659. The reversal of 689121018631 is 136810121986.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136810121986 = 2 ⋅68405060993.

It is a cyclic number.

It is not a de Polignac number, because 689121018631 - 2³ = 689121018623 is a prime.

It is a super-2 number, since 2×689121018631² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689121018601) 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, 2713074750 + ... + 2713075003.

It is an arithmetic number, because the mean of its divisors is an integer number (173636792128).

Almost surely, 2^689121018631 is an apocalyptic number.

689121018631 is a deficient number, since it is larger than the sum of its proper divisors (5426149881).

689121018631 is a wasteful number, since it uses less digits than its factorization.

689121018631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5426149880.

The product of its (nonzero) digits is 124416, while the sum is 46.

The spelling of 689121018631 in words is "six hundred eighty-nine billion, one hundred twenty-one million, eighteen thousand, six hundred thirty-one".