646633171 has 2 divisors, whose sum is σ = 646633172. Its totient is φ = 646633170.

The previous prime is 646633157. The next prime is 646633193. The reversal of 646633171 is 171336646.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646633171 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646633171.

It is not a weakly prime, because it can be changed into another prime (646639171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323316585 + 323316586.

It is an arithmetic number, because the mean of its divisors is an integer number (323316586).

Almost surely, 2^646633171 is an apocalyptic number.

646633171 is a deficient number, since it is larger than the sum of its proper divisors (1).

646633171 is an equidigital number, since it uses as much as digits as its factorization.

646633171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 37.

The square root of 646633171 is about 25428.9828935410. The cubic root of 646633171 is about 864.7408853344.

The spelling of 646633171 in words is "six hundred forty-six million, six hundred thirty-three thousand, one hundred seventy-one".