645808546 has 16 divisors (see below), whose sum is σ = 1028225880. Its totient is φ = 303160320.

The previous prime is 645808519. The next prime is 645808571.

645808546 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 620557921 + 25250625 = 24911^2 + 5025^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645808496 and 645808505.

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, 9315 + ... + 37126.

Almost surely, 2^645808546 is an apocalyptic number.

645808546 is a deficient number, since it is larger than the sum of its proper divisors (382417334).

645808546 is a wasteful number, since it uses less digits than its factorization.

645808546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46869.

The product of its (nonzero) digits is 921600, while the sum is 46.

The square root of 645808546 is about 25412.7634467407. The cubic root of 645808546 is about 864.3731393319.

The spelling of 645808546 in words is "six hundred forty-five million, eight hundred eight thousand, five hundred forty-six".