645815373 has 16 divisors (see below), whose sum is σ = 990621696. Its totient is φ = 366591600.

The previous prime is 645815369. The next prime is 645815389. The reversal of 645815373 is 373518546.

It is not a de Polignac number, because 645815373 - 2² = 645815369 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645815333) 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 in 15 ways as a sum of consecutive naturals, for example, 98661 + ... + 105002.

It is an arithmetic number, because the mean of its divisors is an integer number (61913856).

Almost surely, 2^645815373 is an apocalyptic number.

It is an amenable number.

645815373 is a deficient number, since it is larger than the sum of its proper divisors (344806323).

645815373 is a wasteful number, since it uses less digits than its factorization.

645815373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203824.

The product of its digits is 302400, while the sum is 42.

The square root of 645815373 is about 25412.8977686528. The cubic root of 645815373 is about 864.3761851545.

The spelling of 645815373 in words is "six hundred forty-five million, eight hundred fifteen thousand, three hundred seventy-three".