645365973645 has 24 divisors (see below), whose sum is σ = 1144649110176. Its totient is φ = 336190645728.

The previous prime is 645365973643. The next prime is 645365973653. The reversal of 645365973645 is 546379563546.

645365973645 is a `hidden beast` number, since 6 + 4 + 5 + 3 + 6 + 597 + 36 + 4 + 5 = 666.

It is not a de Polignac number, because 645365973645 - 2¹ = 645365973643 is a prime.

It is a super-3 number, since 3×645365973645³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645365973643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 166759299 + ... + 166763168.

It is an arithmetic number, because the mean of its divisors is an integer number (47693712924).

Almost surely, 2^645365973645 is an apocalyptic number.

It is an amenable number.

645365973645 is a deficient number, since it is larger than the sum of its proper divisors (499283136531).

645365973645 is a wasteful number, since it uses less digits than its factorization.

645365973645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333522521 (or 333522518 counting only the distinct ones).

The product of its digits is 244944000, while the sum is 63.

The spelling of 645365973645 in words is "six hundred forty-five billion, three hundred sixty-five million, nine hundred seventy-three thousand, six hundred forty-five".