661088773 has 4 divisors (see below), whose sum is σ = 662788620. Its totient is φ = 659388928.

The previous prime is 661088761. The next prime is 661088833. The reversal of 661088773 is 377880166.

661088773 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 334816804 + 326271969 = 18298^2 + 18063^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661088773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661088723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 849340 + ... + 850117.

It is an arithmetic number, because the mean of its divisors is an integer number (165697155).

Almost surely, 2^661088773 is an apocalyptic number.

It is an amenable number.

661088773 is a deficient number, since it is larger than the sum of its proper divisors (1699847).

661088773 is a wasteful number, since it uses less digits than its factorization.

661088773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1699846.

The product of its (nonzero) digits is 338688, while the sum is 46.

The square root of 661088773 is about 25711.6466411624. The cubic root of 661088773 is about 871.1372685989.

The spelling of 661088773 in words is "six hundred sixty-one million, eighty-eight thousand, seven hundred seventy-three".