1660261 has 2 divisors, whose sum is σ = 1660262. Its totient is φ = 1660260.

The previous prime is 1660259. The next prime is 1660283. The reversal of 1660261 is 1620661.

It is an a-pointer prime, because the next prime (1660283) can be obtained adding 1660261 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1404225 + 256036 = 1185^2 + 506^2 .

It is a cyclic number.

It is not a de Polignac number, because 1660261 - 2¹ = 1660259 is a prime.

Together with 1660259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660231) 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, 830130 + 830131.

It is an arithmetic number, because the mean of its divisors is an integer number (830131).

2^1660261 is an apocalyptic number.

It is an amenable number.

1660261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660261 is an equidigital number, since it uses as much as digits as its factorization.

1660261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1660261 is about 1288.5111563351. The cubic root of 1660261 is about 118.4110199826.

The spelling of 1660261 in words is "one million, six hundred sixty thousand, two hundred sixty-one".