645252239 has 2 divisors, whose sum is σ = 645252240. Its totient is φ = 645252238.

The previous prime is 645252229. The next prime is 645252241. The reversal of 645252239 is 932252546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645252239 is a prime.

Together with 645252241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645252229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322626119 + 322626120.

It is an arithmetic number, because the mean of its divisors is an integer number (322626120).

Almost surely, 2^645252239 is an apocalyptic number.

645252239 is a deficient number, since it is larger than the sum of its proper divisors (1).

645252239 is an equidigital number, since it uses as much as digits as its factorization.

645252239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 38.

The square root of 645252239 is about 25401.8156634521. The cubic root of 645252239 is about 864.1248743371.

The spelling of 645252239 in words is "six hundred forty-five million, two hundred fifty-two thousand, two hundred thirty-nine".