1684256642 has 4 divisors (see below), whose sum is σ = 2526384966. Its totient is φ = 842128320.

The previous prime is 1684256633. The next prime is 1684256647. The reversal of 1684256642 is 2466524861.

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

It can be written as a sum of positive squares in only one way, i.e., 1684199521 + 57121 = 41039^2 + 239^2 .

It is a super-3 number, since 3×1684256642³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 1684256593 and 1684256602.

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 as a sum of consecutive naturals, namely, 421064159 + ... + 421064162.

Almost surely, 2^1684256642 is an apocalyptic number.

1684256642 is a deficient number, since it is larger than the sum of its proper divisors (842128324).

1684256642 is an equidigital number, since it uses as much as digits as its factorization.

1684256642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842128323.

The product of its digits is 552960, while the sum is 44.

The square root of 1684256642 is about 41039.6959296728. The cubic root of 1684256642 is about 1189.7875575852.

The spelling of 1684256642 in words is "one billion, six hundred eighty-four million, two hundred fifty-six thousand, six hundred forty-two".