499681661 has 2 divisors, whose sum is σ = 499681662. Its totient is φ = 499681660.

The previous prime is 499681657. The next prime is 499681733. The reversal of 499681661 is 166186994.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 495952900 + 3728761 = 22270^2 + 1931^2 .

It is a cyclic number.

It is not a de Polignac number, because 499681661 - 2² = 499681657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (499681621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249840830 + 249840831.

It is an arithmetic number, because the mean of its divisors is an integer number (249840831).

Almost surely, 2^499681661 is an apocalyptic number.

It is an amenable number.

499681661 is a deficient number, since it is larger than the sum of its proper divisors (1).

499681661 is an equidigital number, since it uses as much as digits as its factorization.

499681661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 50.

The square root of 499681661 is about 22353.5603651857. The cubic root of 499681661 is about 793.5320463354.

The spelling of 499681661 in words is "four hundred ninety-nine million, six hundred eighty-one thousand, six hundred sixty-one".