1681627994 has 8 divisors (see below), whose sum is σ = 2524525140. Its totient is φ = 840119616.

The previous prime is 1681627979. The next prime is 1681627999. The reversal of 1681627994 is 4997261861.

It can be written as a sum of positive squares in 2 ways, for example, as 1679770225 + 1857769 = 40985^2 + 1363^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1681627999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 344159 + ... + 349010.

Almost surely, 2^1681627994 is an apocalyptic number.

1681627994 is a deficient number, since it is larger than the sum of its proper divisors (842897146).

1681627994 is a wasteful number, since it uses less digits than its factorization.

1681627994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694384.

The product of its digits is 1306368, while the sum is 53.

The square root of 1681627994 is about 41007.6577482792. The cubic root of 1681627994 is about 1189.1682613959.

The spelling of 1681627994 in words is "one billion, six hundred eighty-one million, six hundred twenty-seven thousand, nine hundred ninety-four".