8049781 has 4 divisors (see below), whose sum is σ = 8121132. Its totient is φ = 7978432.

The previous prime is 8049779. The next prime is 8049803. The reversal of 8049781 is 1879408.

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 260100 + 7789681 = 510^2 + 2791^2 .

It is a cyclic number.

It is not a de Polignac number, because 8049781 - 2¹ = 8049779 is a prime.

It is a super-2 number, since 2×8049781² = 129597948295922, which contains 22 as substring.

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 8049781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8049731) 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, 35506 + ... + 35731.

It is an arithmetic number, because the mean of its divisors is an integer number (2030283).

Almost surely, 2^8049781 is an apocalyptic number.

It is an amenable number.

8049781 is a deficient number, since it is larger than the sum of its proper divisors (71351).

8049781 is a wasteful number, since it uses less digits than its factorization.

8049781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71350.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 8049781 is about 2837.2135978809. The cubic root of 8049781 is about 200.4139841610.

It can be divided in two parts, 804 and 9781, that added together give a triangular number (10585 = T₁₄₅).

The spelling of 8049781 in words is "eight million, forty-nine thousand, seven hundred eighty-one".