645108642 has 24 divisors (see below), whose sum is σ = 1406111616. Its totient is φ = 213747576.

The previous prime is 645108613. The next prime is 645108643. The reversal of 645108642 is 246801546.

645108642 is a `hidden beast` number, since 6 + 4 + 5 + 1 + 0 + 8 + 642 = 666.

645108642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 645108597 and 645108606.

It is not an unprimeable number, because it can be changed into a prime (645108643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104298 + ... + 110309.

It is an arithmetic number, because the mean of its divisors is an integer number (58587984).

Almost surely, 2^645108642 is an apocalyptic number.

645108642 is an abundant number, since it is smaller than the sum of its proper divisors (761002974).

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

645108642 is a wasteful number, since it uses less digits than its factorization.

645108642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214782 (or 214779 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 645108642 is about 25398.9889956274. The cubic root of 645108642 is about 864.0607676524.

The spelling of 645108642 in words is "six hundred forty-five million, one hundred eight thousand, six hundred forty-two".