1684256641 has 4 divisors (see below), whose sum is σ = 1684344832. Its totient is φ = 1684168452.

The previous prime is 1684256633. The next prime is 1684256647. The reversal of 1684256641 is 1466524861.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1684256641 - 2³ = 1684256633 is a prime.

It is a super-3 number, since 3×1684256641³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1684256647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2145 + ... + 58078.

It is an arithmetic number, because the mean of its divisors is an integer number (421086208).

Almost surely, 2^1684256641 is an apocalyptic number.

It is an amenable number.

1684256641 is a deficient number, since it is larger than the sum of its proper divisors (88191).

1684256641 is an equidigital number, since it uses as much as digits as its factorization.

1684256641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88190.

The product of its digits is 276480, while the sum is 43.

The square root of 1684256641 is about 41039.6959174894. The cubic root of 1684256641 is about 1189.7875573497.

The spelling of 1684256641 in words is "one billion, six hundred eighty-four million, two hundred fifty-six thousand, six hundred forty-one".