660172207 has 2 divisors, whose sum is σ = 660172208. Its totient is φ = 660172206.

The previous prime is 660172193. The next prime is 660172213. The reversal of 660172207 is 702271066.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 660172207 - 2²³ = 651783599 is a prime.

It is equal to p_34294711 and since 660172207 and 34294711 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660172267) 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 as a sum of consecutive naturals, namely, 330086103 + 330086104.

It is an arithmetic number, because the mean of its divisors is an integer number (330086104).

Almost surely, 2^660172207 is an apocalyptic number.

660172207 is a deficient number, since it is larger than the sum of its proper divisors (1).

660172207 is an equidigital number, since it uses as much as digits as its factorization.

660172207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 660172207 is about 25693.8165129278. The cubic root of 660172207 is about 870.7344865398.

The spelling of 660172207 in words is "six hundred sixty million, one hundred seventy-two thousand, two hundred seven".