289940821656 has 24 divisors (see below), whose sum is σ = 724858648980. Its totient is φ = 96646061248.

The previous prime is 289940821631. The next prime is 289940821669. The reversal of 289940821656 is 656128049982.

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 289940821656.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 2582956 + ... + 2692868.

Almost surely, 2^289940821656 is an apocalyptic number.

It is an amenable number.

289940821656 is an abundant number, since it is smaller than the sum of its proper divisors (434917827324).

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

289940821656 is an frugal number, since it uses more digits than its factorization.

289940821656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219835 (or 109918 counting only the distinct ones).

The product of its (nonzero) digits is 14929920, while the sum is 60.

The spelling of 289940821656 in words is "two hundred eighty-nine billion, nine hundred forty million, eight hundred twenty-one thousand, six hundred fifty-six".