766861 has 2 divisors, whose sum is σ = 766862. Its totient is φ = 766860.

The previous prime is 766817. The next prime is 766867. The reversal of 766861 is 168667.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 670761 + 96100 = 819^2 + 310^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-766861 is a prime.

766861 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (766867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383430 + 383431.

It is an arithmetic number, because the mean of its divisors is an integer number (383431).

2⁷⁶⁶⁸⁶¹ is an apocalyptic number.

It is an amenable number.

766861 is a deficient number, since it is larger than the sum of its proper divisors (1).

766861 is an equidigital number, since it uses as much as digits as its factorization.

766861 is an evil number, because the sum of its binary digits is even.

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

The square root of 766861 is about 875.7060008930. The cubic root of 766861 is about 91.5318451469.

It can be divided in two parts, 766 and 861, that multiplied together give a triangular number (659526 = T₁₁₄₈).

The spelling of 766861 in words is "seven hundred sixty-six thousand, eight hundred sixty-one".