1516661 has 2 divisors, whose sum is σ = 1516662. Its totient is φ = 1516660.

The previous prime is 1516657. The next prime is 1516663. The reversal of 1516661 is 1666151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1168561 + 348100 = 1081^2 + 590^2 .

It is an emirp because it is prime and its reverse (1666151) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1516661 - 2² = 1516657 is a prime.

It is a Sophie Germain prime.

Together with 1516663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1516661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1516663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 758330 + 758331.

It is an arithmetic number, because the mean of its divisors is an integer number (758331).

2^1516661 is an apocalyptic number.

It is an amenable number.

1516661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1516661 is an equidigital number, since it uses as much as digits as its factorization.

1516661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 26.

The square root of 1516661 is about 1231.5279127978. The cubic root of 1516661 is about 114.8936887709.

The spelling of 1516661 in words is "one million, five hundred sixteen thousand, six hundred sixty-one".