786661 has 2 divisors, whose sum is σ = 786662. Its totient is φ = 786660.

The previous prime is 786659. The next prime is 786673. The reversal of 786661 is 166687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 690561 + 96100 = 831^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 786661 - 2¹ = 786659 is a prime.

Together with 786659, it forms a pair of twin primes.

786661 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (786691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 393330 + 393331.

It is an arithmetic number, because the mean of its divisors is an integer number (393331).

2⁷⁸⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

786661 is a deficient number, since it is larger than the sum of its proper divisors (1).

786661 is an equidigital number, since it uses as much as digits as its factorization.

786661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 786661 is about 886.9391185420. The cubic root of 786661 is about 92.3129309171.

It can be divided in two parts, 7 and 86661, that added together give a palindrome (86668).

The spelling of 786661 in words is "seven hundred eighty-six thousand, six hundred sixty-one".