645695254241 has 2 divisors, whose sum is σ = 645695254242. Its totient is φ = 645695254240.

The previous prime is 645695254223. The next prime is 645695254247. The reversal of 645695254241 is 142452596546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 521089078225 + 124606176016 = 721865^2 + 352996^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645695254241 is a prime.

It is a super-2 number, since 2×645695254241² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645695254247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322847627120 + 322847627121.

It is an arithmetic number, because the mean of its divisors is an integer number (322847627121).

Almost surely, 2^645695254241 is an apocalyptic number.

It is an amenable number.

645695254241 is a deficient number, since it is larger than the sum of its proper divisors (1).

645695254241 is an equidigital number, since it uses as much as digits as its factorization.

645695254241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368000, while the sum is 53.

The spelling of 645695254241 in words is "six hundred forty-five billion, six hundred ninety-five million, two hundred fifty-four thousand, two hundred forty-one".