8219749 has 4 divisors (see below), whose sum is σ = 8267436. Its totient is φ = 8172064.

The previous prime is 8219747. The next prime is 8219777. The reversal of 8219749 is 9479128.

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 4870849 + 3348900 = 2207^2 + 1830^2 .

It is a cyclic number.

It is not a de Polignac number, because 8219749 - 2¹ = 8219747 is a prime.

It is a Duffinian number.

8219749 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8219747) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23584 + ... + 23929.

It is an arithmetic number, because the mean of its divisors is an integer number (2066859).

Almost surely, 2^8219749 is an apocalyptic number.

It is an amenable number.

8219749 is a deficient number, since it is larger than the sum of its proper divisors (47687).

8219749 is a wasteful number, since it uses less digits than its factorization.

8219749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47686.

The product of its digits is 36288, while the sum is 40.

The square root of 8219749 is about 2867.0104638805. The cubic root of 8219749 is about 201.8147257170.

The spelling of 8219749 in words is "eight million, two hundred nineteen thousand, seven hundred forty-nine".