19985436 has 36 divisors (see below), whose sum is σ = 52717392. Its totient is φ = 6371904.

The previous prime is 19985431. The next prime is 19985443. The reversal of 19985436 is 63458991.

It is a happy number.

19985436 is a `hidden beast` number, since 19 + 98 + 543 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×19985436² = 798835304220192, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19985391 and 19985400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19985431) 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 11 ways as a sum of consecutive naturals, for example, 11241 + ... + 12896.

It is an arithmetic number, because the mean of its divisors is an integer number (1464372).

Almost surely, 2^19985436 is an apocalyptic number.

It is an amenable number.

19985436 is an abundant number, since it is smaller than the sum of its proper divisors (32731956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19985436 is a wasteful number, since it uses less digits than its factorization.

19985436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24170 (or 24165 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 19985436 is about 4470.5073537575. The cubic root of 19985436 is about 271.3758576962.

The spelling of 19985436 in words is "nineteen million, nine hundred eighty-five thousand, four hundred thirty-six".