645620006526 has 16 divisors (see below), whose sum is σ = 1408625468928. Its totient is φ = 195642426200.

The previous prime is 645620006503. The next prime is 645620006609. The reversal of 645620006526 is 625600026546.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4891060590 + ... + 4891060721.

It is an arithmetic number, because the mean of its divisors is an integer number (88039091808).

Almost surely, 2^645620006526 is an apocalyptic number.

645620006526 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

645620006526 is an abundant number, since it is smaller than the sum of its proper divisors (763005462402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645620006526 is a wasteful number, since it uses less digits than its factorization.

645620006526 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9782121327.

The product of its (nonzero) digits is 518400, while the sum is 42.

The spelling of 645620006526 in words is "six hundred forty-five billion, six hundred twenty million, six thousand, five hundred twenty-six".