645909546 has 16 divisors (see below), whose sum is σ = 1293220800. Its totient is φ = 215069568.

The previous prime is 645909527. The next prime is 645909557.

645909546 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×645909546² = 834398283227852232, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 645909495 and 645909504.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 52366 + ... + 63513.

It is an arithmetic number, because the mean of its divisors is an integer number (80826300).

Almost surely, 2^645909546 is an apocalyptic number.

645909546 is an abundant number, since it is smaller than the sum of its proper divisors (647311254).

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

645909546 is a wasteful number, since it uses less digits than its factorization.

645909546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116813.

The product of its (nonzero) digits is 1166400, while the sum is 48.

The square root of 645909546 is about 25414.7505594684. The cubic root of 645909546 is about 864.4181976478.

The spelling of 645909546 in words is "six hundred forty-five million, nine hundred nine thousand, five hundred forty-six".