19661798 has 12 divisors (see below), whose sum is σ = 31936428. Its totient is φ = 9074520.

The previous prime is 19661783. The next prime is 19661801. The reversal of 19661798 is 89716691.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 28748 + ... + 29423.

It is an arithmetic number, because the mean of its divisors is an integer number (2661369).

Almost surely, 2^19661798 is an apocalyptic number.

19661798 is a deficient number, since it is larger than the sum of its proper divisors (12274630).

19661798 is a wasteful number, since it uses less digits than its factorization.

19661798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58199 (or 58186 counting only the distinct ones).

The product of its digits is 163296, while the sum is 47.

The square root of 19661798 is about 4434.1626041452. The cubic root of 19661798 is about 269.9030195825.

The spelling of 19661798 in words is "nineteen million, six hundred sixty-one thousand, seven hundred ninety-eight".