684802421 has 4 divisors (see below), whose sum is σ = 685794144. Its totient is φ = 683810700.

The previous prime is 684802403. The next prime is 684802429. The reversal of 684802421 is 124208486.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 684802421 - 2⁶ = 684802357 is a prime.

It is a super-2 number, since 2×684802421² = 937908711614922482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684802429) 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 3 ways as a sum of consecutive naturals, for example, 494825 + ... + 496206.

It is an arithmetic number, because the mean of its divisors is an integer number (171448536).

Almost surely, 2^684802421 is an apocalyptic number.

It is an amenable number.

684802421 is a deficient number, since it is larger than the sum of its proper divisors (991723).

684802421 is an equidigital number, since it uses as much as digits as its factorization.

684802421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991722.

The product of its (nonzero) digits is 24576, while the sum is 35.

The square root of 684802421 is about 26168.7298316139. The cubic root of 684802421 is about 881.4312200055.

The spelling of 684802421 in words is "six hundred eighty-four million, eight hundred two thousand, four hundred twenty-one".