19681994 has 8 divisors (see below), whose sum is σ = 29854980. Its totient is φ = 9730336.

The previous prime is 19681969. The next prime is 19681999. The reversal of 19681994 is 49918691.

19681994 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in 2 ways, for example, as 19669225 + 12769 = 4435^2 + 113^2 .

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

It is not an unprimeable number, because it can be changed into a prime (19681999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55109 + ... + 55464.

Almost surely, 2^19681994 is an apocalyptic number.

19681994 is a deficient number, since it is larger than the sum of its proper divisors (10172986).

19681994 is a wasteful number, since it uses less digits than its factorization.

19681994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110664.

The product of its digits is 139968, while the sum is 47.

The square root of 19681994 is about 4436.4393380277. The cubic root of 19681994 is about 269.9954000131.

The spelling of 19681994 in words is "nineteen million, six hundred eighty-one thousand, nine hundred ninety-four".