645891052277 has 2 divisors, whose sum is σ = 645891052278. Its totient is φ = 645891052276.

The previous prime is 645891052187. The next prime is 645891052291. The reversal of 645891052277 is 772250198546.

645891052277 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 645887076241 + 3976036 = 803671^2 + 1994^2 .

It is a cyclic number.

It is not a de Polignac number, because 645891052277 - 2¹⁸ = 645890790133 is a prime.

It is a super-2 number, since 2×645891052277² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645891552277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322945526138 + 322945526139.

It is an arithmetic number, because the mean of its divisors is an integer number (322945526139).

Almost surely, 2^645891052277 is an apocalyptic number.

It is an amenable number.

645891052277 is a deficient number, since it is larger than the sum of its proper divisors (1).

645891052277 is an equidigital number, since it uses as much as digits as its factorization.

645891052277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8467200, while the sum is 56.

The spelling of 645891052277 in words is "six hundred forty-five billion, eight hundred ninety-one million, fifty-two thousand, two hundred seventy-seven".