19987796 has 6 divisors (see below), whose sum is σ = 34978650. Its totient is φ = 9993896.

The previous prime is 19987789. The next prime is 19987813. The reversal of 19987796 is 69778991.

It can be written as a sum of positive squares in only one way, i.e., 17472400 + 2515396 = 4180^2 + 1586^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2498471 + ... + 2498478.

It is an arithmetic number, because the mean of its divisors is an integer number (5829775).

Almost surely, 2^19987796 is an apocalyptic number.

It is an amenable number.

19987796 is a deficient number, since it is larger than the sum of its proper divisors (14990854).

19987796 is a wasteful number, since it uses less digits than its factorization.

19987796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4996953 (or 4996951 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 56.

The square root of 19987796 is about 4470.7712981095. The cubic root of 19987796 is about 271.3865391714.

The spelling of 19987796 in words is "nineteen million, nine hundred eighty-seven thousand, seven hundred ninety-six".