775450661 has 4 divisors (see below), whose sum is σ = 775506732. Its totient is φ = 775394592.

The previous prime is 775450619. The next prime is 775450673. The reversal of 775450661 is 166054577.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 166054577 = 13 ⋅12773429.

It can be written as a sum of positive squares in 2 ways, for example, as 641608900 + 133841761 = 25330^2 + 11569^2 .

It is a cyclic number.

It is not a de Polignac number, because 775450661 - 2²⁶ = 708341797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775450061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9155 + ... + 40431.

It is an arithmetic number, because the mean of its divisors is an integer number (193876683).

Almost surely, 2^775450661 is an apocalyptic number.

It is an amenable number.

775450661 is a deficient number, since it is larger than the sum of its proper divisors (56071).

775450661 is a wasteful number, since it uses less digits than its factorization.

775450661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56070.

The product of its (nonzero) digits is 176400, while the sum is 41.

The square root of 775450661 is about 27846.9147483164. The cubic root of 775450661 is about 918.7232846074.

The spelling of 775450661 in words is "seven hundred seventy-five million, four hundred fifty thousand, six hundred sixty-one".