661661307 has 6 divisors (see below), whose sum is σ = 955733012. Its totient is φ = 441107532.

The previous prime is 661661281. The next prime is 661661311. The reversal of 661661307 is 703166166.

661661307 is a `hidden beast` number, since 6 + 616 + 6 + 1 + 30 + 7 = 666.

It is not a de Polignac number, because 661661307 - 2¹⁰ = 661660283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661661317) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36758953 + ... + 36758970.

Almost surely, 2^661661307 is an apocalyptic number.

661661307 is a deficient number, since it is larger than the sum of its proper divisors (294071705).

661661307 is a wasteful number, since it uses less digits than its factorization.

661661307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73517929 (or 73517926 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 661661307 is about 25722.7779798372. Note that the first 3 decimals coincide. The cubic root of 661661307 is about 871.3886779974.

The spelling of 661661307 in words is "six hundred sixty-one million, six hundred sixty-one thousand, three hundred seven".