689440993851 has 4 divisors (see below), whose sum is σ = 919254658472. Its totient is φ = 459627329232.

The previous prime is 689440993849. The next prime is 689440993859. The reversal of 689440993851 is 158399044986.

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

It is not a de Polignac number, because 689440993851 - 2¹ = 689440993849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689440993859) 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, 114906832306 + ... + 114906832311.

It is an arithmetic number, because the mean of its divisors is an integer number (229813664618).

Almost surely, 2^689440993851 is an apocalyptic number.

689440993851 is a deficient number, since it is larger than the sum of its proper divisors (229813664621).

689440993851 is a wasteful number, since it uses less digits than its factorization.

689440993851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229813664620.

The product of its (nonzero) digits is 67184640, while the sum is 66.

The spelling of 689440993851 in words is "six hundred eighty-nine billion, four hundred forty million, nine hundred ninety-three thousand, eight hundred fifty-one".