645642063 has 16 divisors (see below), whose sum is σ = 1043462400. Its totient is φ = 391298040.

The previous prime is 645642061. The next prime is 645642077. The reversal of 645642063 is 360246546.

645642063 is a `hidden beast` number, since 6 + 4 + 5 + 642 + 0 + 6 + 3 = 666.

It is not a de Polignac number, because 645642063 - 2¹ = 645642061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645642061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1086643 + ... + 1087236.

It is an arithmetic number, because the mean of its divisors is an integer number (65216400).

Almost surely, 2^645642063 is an apocalyptic number.

645642063 is a deficient number, since it is larger than the sum of its proper divisors (397820337).

645642063 is a wasteful number, since it uses less digits than its factorization.

645642063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2173899 (or 2173893 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 645642063 is about 25409.4876571725. The cubic root of 645642063 is about 864.2988573580.

The spelling of 645642063 in words is "six hundred forty-five million, six hundred forty-two thousand, sixty-three".