645009012 has 72 divisors (see below), whose sum is σ = 1710299136. Its totient is φ = 204721344.

The previous prime is 645008999. The next prime is 645009037. The reversal of 645009012 is 210900546.

645009012 is a `hidden beast` number, since 64 + 500 + 90 + 12 = 666.

It is a super-2 number, since 2×645009012² = 832073251122432288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57453 + ... + 67755.

Almost surely, 2^645009012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645009012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (855149568).

645009012 is an abundant number, since it is smaller than the sum of its proper divisors (1065290124).

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

645009012 is a wasteful number, since it uses less digits than its factorization.

645009012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10397 (or 10392 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 645009012 is about 25397.0276213576. The cubic root of 645009012 is about 864.0162837723.

Adding to 645009012 its reverse (210900546), we get a palindrome (855909558).

The spelling of 645009012 in words is "six hundred forty-five million, nine thousand, twelve".