645611422171 has 2 divisors, whose sum is σ = 645611422172. Its totient is φ = 645611422170.

The previous prime is 645611422151. The next prime is 645611422207. The reversal of 645611422171 is 171224116546.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645611422171 - 2⁹ = 645611421659 is a prime.

It is a super-2 number, since 2×645611422171² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645611422151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322805711085 + 322805711086.

It is an arithmetic number, because the mean of its divisors is an integer number (322805711086).

Almost surely, 2^645611422171 is an apocalyptic number.

645611422171 is a deficient number, since it is larger than the sum of its proper divisors (1).

645611422171 is an equidigital number, since it uses as much as digits as its factorization.

645611422171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 40.

The spelling of 645611422171 in words is "six hundred forty-five billion, six hundred eleven million, four hundred twenty-two thousand, one hundred seventy-one".