645166139 has 2 divisors, whose sum is σ = 645166140. Its totient is φ = 645166138.

The previous prime is 645166129. The next prime is 645166157. The reversal of 645166139 is 931661546.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645166139 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 645166096 and 645166105.

It is not a weakly prime, because it can be changed into another prime (645166129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322583069 + 322583070.

It is an arithmetic number, because the mean of its divisors is an integer number (322583070).

Almost surely, 2^645166139 is an apocalyptic number.

645166139 is a deficient number, since it is larger than the sum of its proper divisors (1).

645166139 is an equidigital number, since it uses as much as digits as its factorization.

645166139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 41.

The square root of 645166139 is about 25400.1208461692. The cubic root of 645166139 is about 864.0864374506.

The spelling of 645166139 in words is "six hundred forty-five million, one hundred sixty-six thousand, one hundred thirty-nine".