684464024021 has 4 divisors (see below), whose sum is σ = 687401638092. Its totient is φ = 681526409952.

The previous prime is 684464024017. The next prime is 684464024071. The reversal of 684464024021 is 120420464486.

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

It can be written as a sum of positive squares in 2 ways, for example, as 119695240900 + 564768783121 = 345970^2 + 751511^2 .

It is a cyclic number.

It is not a de Polignac number, because 684464024021 - 2² = 684464024017 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 684464024021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684464024071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1468806686 + ... + 1468807151.

It is an arithmetic number, because the mean of its divisors is an integer number (171850409523).

Almost surely, 2^684464024021 is an apocalyptic number.

It is an amenable number.

684464024021 is a deficient number, since it is larger than the sum of its proper divisors (2937614071).

684464024021 is a wasteful number, since it uses less digits than its factorization.

684464024021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2937614070.

The product of its (nonzero) digits is 294912, while the sum is 41.

The spelling of 684464024021 in words is "six hundred eighty-four billion, four hundred sixty-four million, twenty-four thousand, twenty-one".