645234829 has 2 divisors, whose sum is σ = 645234830. Its totient is φ = 645234828.

The previous prime is 645234827. The next prime is 645234839. The reversal of 645234829 is 928432546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 532917225 + 112317604 = 23085^2 + 10598^2 .

It is a cyclic number.

It is not a de Polignac number, because 645234829 - 2¹ = 645234827 is a prime.

Together with 645234827, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645234827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322617414 + 322617415.

It is an arithmetic number, because the mean of its divisors is an integer number (322617415).

Almost surely, 2^645234829 is an apocalyptic number.

It is an amenable number.

645234829 is a deficient number, since it is larger than the sum of its proper divisors (1).

645234829 is an equidigital number, since it uses as much as digits as its factorization.

645234829 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 414720, while the sum is 43.

The square root of 645234829 is about 25401.4729691016. The cubic root of 645234829 is about 864.1171024155.

The spelling of 645234829 in words is "six hundred forty-five million, two hundred thirty-four thousand, eight hundred twenty-nine".