4399781 has 4 divisors (see below), whose sum is σ = 4518732. Its totient is φ = 4280832.

The previous prime is 4399771. The next prime is 4399789. The reversal of 4399781 is 1879934.

It is a happy number.

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 1934881 + 2464900 = 1391^2 + 1570^2 .

It is a cyclic number.

It is not a de Polignac number, because 4399781 - 2¹⁴ = 4383397 is a prime.

It is a super-3 number, since 3×4399781³ (a number of 21 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4399789) 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, 59420 + ... + 59493.

It is an arithmetic number, because the mean of its divisors is an integer number (1129683).

Almost surely, 2^4399781 is an apocalyptic number.

It is an amenable number.

4399781 is a deficient number, since it is larger than the sum of its proper divisors (118951).

4399781 is a wasteful number, since it uses less digits than its factorization.

4399781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118950.

The product of its digits is 54432, while the sum is 41.

The square root of 4399781 is about 2097.5654936140. The cubic root of 4399781 is about 163.8615354181.

The spelling of 4399781 in words is "four million, three hundred ninety-nine thousand, seven hundred eighty-one".