645217426 has 16 divisors (see below), whose sum is σ = 1118517120. Its totient is φ = 273414240.

The previous prime is 645217423. The next prime is 645217429. The reversal of 645217426 is 624712546.

645217426 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645217423) and next prime (645217429).

It is not an unprimeable number, because it can be changed into a prime (645217423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257670 + ... + 260161.

It is an arithmetic number, because the mean of its divisors is an integer number (69907320).

Almost surely, 2^645217426 is an apocalyptic number.

645217426 is a deficient number, since it is larger than the sum of its proper divisors (473299694).

645217426 is a wasteful number, since it uses less digits than its factorization.

645217426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517929.

The product of its digits is 80640, while the sum is 37.

The square root of 645217426 is about 25401.1304079169. The cubic root of 645217426 is about 864.1093334791.

The spelling of 645217426 in words is "six hundred forty-five million, two hundred seventeen thousand, four hundred twenty-six".