645885241 has 16 divisors (see below), whose sum is σ = 691384320. Its totient is φ = 601912080.

The previous prime is 645885223. The next prime is 645885257. The reversal of 645885241 is 142588546.

It is a cyclic number.

It is not a de Polignac number, because 645885241 - 2⁷ = 645885113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645885041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 651256 + ... + 652246.

It is an arithmetic number, because the mean of its divisors is an integer number (43211520).

Almost surely, 2^645885241 is an apocalyptic number.

645885241 is the 13585-th centered heptagonal number.

It is an amenable number.

645885241 is a deficient number, since it is larger than the sum of its proper divisors (45499079).

645885241 is a wasteful number, since it uses less digits than its factorization.

645885241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716.

The product of its digits is 307200, while the sum is 43.

The square root of 645885241 is about 25414.2723877746. The cubic root of 645885241 is about 864.4073550833.

The spelling of 645885241 in words is "six hundred forty-five million, eight hundred eighty-five thousand, two hundred forty-one".