645034243 has 4 divisors (see below), whose sum is σ = 737182000. Its totient is φ = 552886488.

The previous prime is 645034231. The next prime is 645034253. The reversal of 645034243 is 342430546.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 645034243 - 2²⁵ = 611479811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645034253) 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 in 3 ways as a sum of consecutive naturals, for example, 46073868 + ... + 46073881.

It is an arithmetic number, because the mean of its divisors is an integer number (184295500).

Almost surely, 2^645034243 is an apocalyptic number.

645034243 is a deficient number, since it is larger than the sum of its proper divisors (92147757).

645034243 is an equidigital number, since it uses as much as digits as its factorization.

645034243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92147756.

The product of its (nonzero) digits is 34560, while the sum is 31.

The square root of 645034243 is about 25397.5243478572. The cubic root of 645034243 is about 864.0275496152.

Adding to 645034243 its reverse (342430546), we get a palindrome (987464789).

The spelling of 645034243 in words is "six hundred forty-five million, thirty-four thousand, two hundred forty-three".