19778441 has 4 divisors (see below), whose sum is σ = 20260884. Its totient is φ = 19296000.

The previous prime is 19778431. The next prime is 19778443. The reversal of 19778441 is 14487791.

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 3610000 + 16168441 = 1900^2 + 4021^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19778441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 482401 = 19778441 / (1 + 9 + 7 + 7 + 8 + 4 + 4 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19778443) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 241160 + ... + 241241.

It is an arithmetic number, because the mean of its divisors is an integer number (5065221).

Almost surely, 2^19778441 is an apocalyptic number.

It is an amenable number.

19778441 is a deficient number, since it is larger than the sum of its proper divisors (482443).

19778441 is an equidigital number, since it uses as much as digits as its factorization.

19778441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482442.

The product of its digits is 56448, while the sum is 41.

The square root of 19778441 is about 4447.2959199945. The cubic root of 19778441 is about 270.4356980008.

The spelling of 19778441 in words is "nineteen million, seven hundred seventy-eight thousand, four hundred forty-one".