661768207 has 4 divisors (see below), whose sum is σ = 664123536. Its totient is φ = 659412880.

The previous prime is 661768201. The next prime is 661768223. The reversal of 661768207 is 702867166.

661768207 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 is a cyclic number.

It is not a de Polignac number, because 661768207 - 2¹¹ = 661766159 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 (661768201) 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, 1177243 + ... + 1177804.

It is an arithmetic number, because the mean of its divisors is an integer number (166030884).

Almost surely, 2^661768207 is an apocalyptic number.

661768207 is a deficient number, since it is larger than the sum of its proper divisors (2355329).

661768207 is a wasteful number, since it uses less digits than its factorization.

661768207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2355328.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 661768207 is about 25724.8558207816. The cubic root of 661768207 is about 871.4356035329.

The spelling of 661768207 in words is "six hundred sixty-one million, seven hundred sixty-eight thousand, two hundred seven".