766416521 has 12 divisors (see below), whose sum is σ = 832431132. Its totient is φ = 705309696.

The previous prime is 766416499. The next prime is 766416523. The reversal of 766416521 is 125614667.

It can be written as a sum of positive squares in 6 ways, for example, as 12145225 + 754271296 = 3485^2 + 27464^2 .

It is a de Polignac number, because none of the positive numbers 2^k-766416521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (766416523) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50225 + ... + 63681.

It is an arithmetic number, because the mean of its divisors is an integer number (69369261).

Almost surely, 2^766416521 is an apocalyptic number.

It is an amenable number.

766416521 is a deficient number, since it is larger than the sum of its proper divisors (66014611).

766416521 is a wasteful number, since it uses less digits than its factorization.

766416521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13820 (or 13807 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 766416521 is about 27684.2287412888. The cubic root of 766416521 is about 915.1415752347.

The spelling of 766416521 in words is "seven hundred sixty-six million, four hundred sixteen thousand, five hundred twenty-one".