661307305 has 8 divisors (see below), whose sum is σ = 794449152. Its totient is φ = 528458928.

The previous prime is 661307303. The next prime is 661307321. The reversal of 661307305 is 503703166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661307305 - 2¹ = 661307303 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661307303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68377 + ... + 77446.

It is an arithmetic number, because the mean of its divisors is an integer number (99306144).

Almost surely, 2^661307305 is an apocalyptic number.

It is an amenable number.

661307305 is a deficient number, since it is larger than the sum of its proper divisors (133141847).

661307305 is a wasteful number, since it uses less digits than its factorization.

661307305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146735.

The product of its (nonzero) digits is 11340, while the sum is 31.

The square root of 661307305 is about 25715.8959595033. The cubic root of 661307305 is about 871.2332468319.

The spelling of 661307305 in words is "six hundred sixty-one million, three hundred seven thousand, three hundred five".