1683721642 has 4 divisors (see below), whose sum is σ = 2525582466. Its totient is φ = 841860820.

The previous prime is 1683721639. The next prime is 1683721657. The reversal of 1683721642 is 2461273861.

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., 1263020521 + 420701121 = 35539^2 + 20511^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 1683721595 and 1683721604.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420930409 + ... + 420930412.

Almost surely, 2^1683721642 is an apocalyptic number.

1683721642 is a deficient number, since it is larger than the sum of its proper divisors (841860824).

1683721642 is an equidigital number, since it uses as much as digits as its factorization.

1683721642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841860823.

The product of its digits is 96768, while the sum is 40.

The square root of 1683721642 is about 41033.1773324952. The cubic root of 1683721642 is about 1189.6615665421.

The spelling of 1683721642 in words is "one billion, six hundred eighty-three million, seven hundred twenty-one thousand, six hundred forty-two".