645929556 has 12 divisors (see below), whose sum is σ = 1507168992. Its totient is φ = 215309848.

The previous prime is 645929551. The next prime is 645929579. The reversal of 645929556 is 655929546.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 645929499 and 645929508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645929551) 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, 26913720 + ... + 26913743.

It is an arithmetic number, because the mean of its divisors is an integer number (125597416).

Almost surely, 2^645929556 is an apocalyptic number.

It is an amenable number.

645929556 is an abundant number, since it is smaller than the sum of its proper divisors (861239436).

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

645929556 is a wasteful number, since it uses less digits than its factorization.

645929556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53827470 (or 53827468 counting only the distinct ones).

The product of its digits is 2916000, while the sum is 51.

The square root of 645929556 is about 25415.1442254416. The cubic root of 645929556 is about 864.4271239903.

The spelling of 645929556 in words is "six hundred forty-five million, nine hundred twenty-nine thousand, five hundred fifty-six".