645552211 has 2 divisors, whose sum is σ = 645552212. Its totient is φ = 645552210.

The previous prime is 645552197. The next prime is 645552221. The reversal of 645552211 is 112255546.

645552211 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 is a cyclic number.

It is not a de Polignac number, because 645552211 - 2²³ = 637163603 is a prime.

It is not a weakly prime, because it can be changed into another prime (645552221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322776105 + 322776106.

It is an arithmetic number, because the mean of its divisors is an integer number (322776106).

Almost surely, 2^645552211 is an apocalyptic number.

645552211 is a deficient number, since it is larger than the sum of its proper divisors (1).

645552211 is an equidigital number, since it uses as much as digits as its factorization.

645552211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12000, while the sum is 31.

The square root of 645552211 is about 25407.7195159267. The cubic root of 645552211 is about 864.2587615690.

It can be divided in two parts, 64555 and 2211, that added together give a palindrome (66766).

The spelling of 645552211 in words is "six hundred forty-five million, five hundred fifty-two thousand, two hundred eleven".