499781 has 2 divisors, whose sum is σ = 499782. Its totient is φ = 499780.

The previous prime is 499747. The next prime is 499787. The reversal of 499781 is 187994.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 429025 + 70756 = 655^2 + 266^2 .

It is a cyclic number.

It is not a de Polignac number, because 499781 - 2⁶ = 499717 is a prime.

It is a super-2 number, since 2×499781² = 499562095922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (499787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249890 + 249891.

It is an arithmetic number, because the mean of its divisors is an integer number (249891).

2⁴⁹⁹⁷⁸¹ is an apocalyptic number.

It is an amenable number.

499781 is a deficient number, since it is larger than the sum of its proper divisors (1).

499781 is an equidigital number, since it uses as much as digits as its factorization.

499781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 38.

The square root of 499781 is about 706.9519078410. The cubic root of 499781 is about 79.3584628785.

The spelling of 499781 in words is "four hundred ninety-nine thousand, seven hundred eighty-one".