645540646171 has 2 divisors, whose sum is σ = 645540646172. Its totient is φ = 645540646170.

The previous prime is 645540646133. The next prime is 645540646183. The reversal of 645540646171 is 171646045546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645540646171 is a prime.

It is a super-2 number, since 2×645540646171² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645540646271) 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, 322770323085 + 322770323086.

It is an arithmetic number, because the mean of its divisors is an integer number (322770323086).

Almost surely, 2^645540646171 is an apocalyptic number.

645540646171 is a deficient number, since it is larger than the sum of its proper divisors (1).

645540646171 is an equidigital number, since it uses as much as digits as its factorization.

645540646171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2419200, while the sum is 49.

The spelling of 645540646171 in words is "six hundred forty-five billion, five hundred forty million, six hundred forty-six thousand, one hundred seventy-one".