19997698 has 16 divisors (see below), whose sum is σ = 34429824. Its totient is φ = 8533440.

The previous prime is 19997689. The next prime is 19997699. The reversal of 19997698 is 89679991.

It is not an unprimeable number, because it can be changed into a prime (19997699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 411 + ... + 6337.

It is an arithmetic number, because the mean of its divisors is an integer number (2151864).

Almost surely, 2^19997698 is an apocalyptic number.

19997698 is a deficient number, since it is larger than the sum of its proper divisors (14432126).

19997698 is a wasteful number, since it uses less digits than its factorization.

19997698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6177.

The product of its digits is 2204496, while the sum is 58.

The square root of 19997698 is about 4471.8785761691. The cubic root of 19997698 is about 271.4313469443.

The spelling of 19997698 in words is "nineteen million, nine hundred ninety-seven thousand, six hundred ninety-eight".