645172519 has 2 divisors, whose sum is σ = 645172520. Its totient is φ = 645172518.

The previous prime is 645172513. The next prime is 645172537. The reversal of 645172519 is 915271546.

645172519 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645172519 - 2⁷ = 645172391 is a prime.

It is a super-2 number, since 2×645172519² = 832495158545610722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645172513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322586259 + 322586260.

It is an arithmetic number, because the mean of its divisors is an integer number (322586260).

Almost surely, 2^645172519 is an apocalyptic number.

645172519 is a deficient number, since it is larger than the sum of its proper divisors (1).

645172519 is an equidigital number, since it uses as much as digits as its factorization.

645172519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 40.

The square root of 645172519 is about 25400.2464358124. The cubic root of 645172519 is about 864.0892857367.

The spelling of 645172519 in words is "six hundred forty-five million, one hundred seventy-two thousand, five hundred nineteen".