645330026 has 32 divisors (see below), whose sum is σ = 1072526400. Its totient is φ = 291184080.

The previous prime is 645330017. The next prime is 645330029. The reversal of 645330026 is 620033546.

It is a super-4 number, since 4×645330026⁴ (a number of 36 digits) contains 4444 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (645330029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 395825 + ... + 397451.

It is an arithmetic number, because the mean of its divisors is an integer number (33516450).

Almost surely, 2^645330026 is an apocalyptic number.

645330026 is a deficient number, since it is larger than the sum of its proper divisors (427196374).

645330026 is a wasteful number, since it uses less digits than its factorization.

645330026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1811 (or 1789 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 29.

The square root of 645330026 is about 25403.3467480173. The cubic root of 645330026 is about 864.1595971822.

The spelling of 645330026 in words is "six hundred forty-five million, three hundred thirty thousand, twenty-six".