19859849 has 4 divisors (see below), whose sum is σ = 19903764. Its totient is φ = 19815936.

The previous prime is 19859843. The next prime is 19859857. The reversal of 19859849 is 94895891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14684224 + 5175625 = 3832^2 + 2275^2 .

It is a cyclic number.

It is not a de Polignac number, because 19859849 - 2¹² = 19855753 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19859849.

It is not an unprimeable number, because it can be changed into a prime (19859843) 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, 21272 + ... + 22185.

It is an arithmetic number, because the mean of its divisors is an integer number (4975941).

Almost surely, 2^19859849 is an apocalyptic number.

It is an amenable number.

19859849 is a deficient number, since it is larger than the sum of its proper divisors (43915).

19859849 is an equidigital number, since it uses as much as digits as its factorization.

19859849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43914.

The product of its digits is 933120, while the sum is 53.

The square root of 19859849 is about 4456.4390492859. The cubic root of 19859849 is about 270.8062275884.

The spelling of 19859849 in words is "nineteen million, eight hundred fifty-nine thousand, eight hundred forty-nine".