645133836 has 12 divisors (see below), whose sum is σ = 1505312312. Its totient is φ = 215044608.

The previous prime is 645133807. The next prime is 645133927. The reversal of 645133836 is 638331546.

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 = 645133794 and 645133803.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26880565 + ... + 26880588.

Almost surely, 2^645133836 is an apocalyptic number.

It is an amenable number.

645133836 is an abundant number, since it is smaller than the sum of its proper divisors (860178476).

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

645133836 is a wasteful number, since it uses less digits than its factorization.

645133836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53761160 (or 53761158 counting only the distinct ones).

The product of its digits is 155520, while the sum is 39.

The square root of 645133836 is about 25399.4849554081. The cubic root of 645133836 is about 864.0720158165.

The spelling of 645133836 in words is "six hundred forty-five million, one hundred thirty-three thousand, eight hundred thirty-six".