645464016 has 30 divisors (see below), whose sum is σ = 1806403170. Its totient is φ = 215154624.

The previous prime is 645464011. The next prime is 645464021. The reversal of 645464016 is 610464546.

645464016 is a `hidden beast` number, since 6 + 4 + 5 + 4 + 640 + 1 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (645464011) and next prime (645464021).

It can be written as a sum of positive squares in only one way, i.e., 497111616 + 148352400 = 22296^2 + 12180^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645464011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2241051 + ... + 2241338.

It is an arithmetic number, because the mean of its divisors is an integer number (60213439).

Almost surely, 2^645464016 is an apocalyptic number.

It is an amenable number.

645464016 is an abundant number, since it is smaller than the sum of its proper divisors (1160939154).

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

645464016 is a wasteful number, since it uses less digits than its factorization.

645464016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4482403 (or 4482394 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 645464016 is about 25405.9838620747. The cubic root of 645464016 is about 864.2194015856.

The spelling of 645464016 in words is "six hundred forty-five million, four hundred sixty-four thousand, sixteen".