645053639 has 2 divisors, whose sum is σ = 645053640. Its totient is φ = 645053638.

The previous prime is 645053603. The next prime is 645053663. The reversal of 645053639 is 936350546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645053639 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 645053596 and 645053605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645053939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322526819 + 322526820.

It is an arithmetic number, because the mean of its divisors is an integer number (322526820).

Almost surely, 2^645053639 is an apocalyptic number.

645053639 is a deficient number, since it is larger than the sum of its proper divisors (1).

645053639 is an equidigital number, since it uses as much as digits as its factorization.

645053639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 291600, while the sum is 41.

The square root of 645053639 is about 25397.9061932278. The cubic root of 645053639 is about 864.0362098843.

The spelling of 645053639 in words is "six hundred forty-five million, fifty-three thousand, six hundred thirty-nine".