766885661 has 2 divisors, whose sum is σ = 766885662. Its totient is φ = 766885660.

The previous prime is 766885649. The next prime is 766885667. The reversal of 766885661 is 166588667.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639331225 + 127554436 = 25285^2 + 11294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-766885661 is a prime.

It is a super-2 number, since 2×766885661² = 1176227234094813842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (766885667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383442830 + 383442831.

It is an arithmetic number, because the mean of its divisors is an integer number (383442831).

Almost surely, 2^766885661 is an apocalyptic number.

It is an amenable number.

766885661 is a deficient number, since it is larger than the sum of its proper divisors (1).

766885661 is an equidigital number, since it uses as much as digits as its factorization.

766885661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2903040, while the sum is 53.

The square root of 766885661 is about 27692.7005003124. The cubic root of 766885661 is about 915.3282630805.

The spelling of 766885661 in words is "seven hundred sixty-six million, eight hundred eighty-five thousand, six hundred sixty-one".