645643808011 has 2 divisors, whose sum is σ = 645643808012. Its totient is φ = 645643808010.

The previous prime is 645643807961. The next prime is 645643808057. The reversal of 645643808011 is 110808346546.

It is an a-pointer prime, because the next prime (645643808057) can be obtained adding 645643808011 to its sum of digits (46).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645643808011 - 2¹⁵ = 645643775243 is a prime.

It is a super-2 number, since 2×645643808011² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645643808611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322821904005 + 322821904006.

It is an arithmetic number, because the mean of its divisors is an integer number (322821904006).

Almost surely, 2^645643808011 is an apocalyptic number.

645643808011 is a deficient number, since it is larger than the sum of its proper divisors (1).

645643808011 is an equidigital number, since it uses as much as digits as its factorization.

645643808011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 552960, while the sum is 46.

The spelling of 645643808011 in words is "six hundred forty-five billion, six hundred forty-three million, eight hundred eight thousand, eleven".