684875521 has 8 divisors (see below), whose sum is σ = 765360288. Its totient is φ = 607428000.

The previous prime is 684875509. The next prime is 684875627. The reversal of 684875521 is 125578486.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 684875521 - 2⁵ = 684875489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (684872521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 758835 + ... + 759736.

It is an arithmetic number, because the mean of its divisors is an integer number (95670036).

Almost surely, 2^684875521 is an apocalyptic number.

It is an amenable number.

684875521 is a deficient number, since it is larger than the sum of its proper divisors (80484767).

684875521 is a wasteful number, since it uses less digits than its factorization.

684875521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1518623.

The product of its digits is 537600, while the sum is 46.

The square root of 684875521 is about 26170.1264995032. The cubic root of 684875521 is about 881.4625820100.

It can be divided in two parts, 6848 and 75521, that added together give a square (82369 = 287²).

The spelling of 684875521 in words is "six hundred eighty-four million, eight hundred seventy-five thousand, five hundred twenty-one".