684155216653 has 4 divisors (see below), whose sum is σ = 724399641180. Its totient is φ = 643910792128.

The previous prime is 684155216651. The next prime is 684155216659. The reversal of 684155216653 is 356612551486.

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 200549021929 + 483606194724 = 447827^2 + 695418^2 .

It is a cyclic number.

It is not a de Polignac number, because 684155216653 - 2¹ = 684155216651 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 684155216653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684155216651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20122212238 + ... + 20122212271.

It is an arithmetic number, because the mean of its divisors is an integer number (181099910295).

Almost surely, 2^684155216653 is an apocalyptic number.

It is an amenable number.

684155216653 is a deficient number, since it is larger than the sum of its proper divisors (40244424527).

684155216653 is a wasteful number, since it uses less digits than its factorization.

684155216653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40244424526.

The product of its digits is 5184000, while the sum is 52.

The spelling of 684155216653 in words is "six hundred eighty-four billion, one hundred fifty-five million, two hundred sixteen thousand, six hundred fifty-three".