766630661 has 2 divisors, whose sum is σ = 766630662. Its totient is φ = 766630660.

The previous prime is 766630649. The next prime is 766630679. The reversal of 766630661 is 166036667.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 558376900 + 208253761 = 23630^2 + 14431^2 .

It is an emirp because it is prime and its reverse (166036667) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 766630661 - 2²² = 762436357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (766630561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383315330 + 383315331.

It is an arithmetic number, because the mean of its divisors is an integer number (383315331).

Almost surely, 2^766630661 is an apocalyptic number.

It is an amenable number.

766630661 is a deficient number, since it is larger than the sum of its proper divisors (1).

766630661 is an equidigital number, since it uses as much as digits as its factorization.

766630661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 41.

The square root of 766630661 is about 27688.0960161583. The cubic root of 766630661 is about 915.2267987665.

The spelling of 766630661 in words is "seven hundred sixty-six million, six hundred thirty thousand, six hundred sixty-one".