499981 has 4 divisors (see below), whose sum is σ = 513532. Its totient is φ = 486432.

The previous prime is 499979. The next prime is 500009. The reversal of 499981 is 189994.

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 366025 + 133956 = 605^2 + 366^2 .

It is a cyclic number.

It is not a de Polignac number, because 499981 - 2¹ = 499979 is a prime.

It is a super-2 number, since 2×499981² = 499962000722, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (499181) 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, 6720 + ... + 6793.

It is an arithmetic number, because the mean of its divisors is an integer number (128383).

2⁴⁹⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

499981 is a deficient number, since it is larger than the sum of its proper divisors (13551).

499981 is a wasteful number, since it uses less digits than its factorization.

499981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13550.

The product of its digits is 23328, while the sum is 40.

The square root of 499981 is about 707.0933460301. The cubic root of 499981 is about 79.3690472317.

The spelling of 499981 in words is "four hundred ninety-nine thousand, nine hundred eighty-one".