645441007 has 4 divisors (see below), whose sum is σ = 652095136. Its totient is φ = 638786880.

The previous prime is 645440977. The next prime is 645441011. The reversal of 645441007 is 700144546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645441007 - 2¹⁹ = 644916719 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645441007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645441037) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3326919 + ... + 3327112.

It is an arithmetic number, because the mean of its divisors is an integer number (163023784).

Almost surely, 2^645441007 is an apocalyptic number.

645441007 is a deficient number, since it is larger than the sum of its proper divisors (6654129).

645441007 is an equidigital number, since it uses as much as digits as its factorization.

645441007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6654128.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 645441007 is about 25405.5310316474. The cubic root of 645441007 is about 864.2091324562.

The spelling of 645441007 in words is "six hundred forty-five million, four hundred forty-one thousand, seven".