645547617 has 32 divisors (see below), whose sum is σ = 1123570560. Its totient is φ = 361143360.

The previous prime is 645547607. The next prime is 645547619. The reversal of 645547617 is 716745546.

645547617 is a `hidden beast` number, since 6 + 45 + 547 + 61 + 7 = 666.

It is not a de Polignac number, because 645547617 - 2⁷ = 645547489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645547619) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79738 + ... + 87459.

It is an arithmetic number, because the mean of its divisors is an integer number (35111580).

Almost surely, 2^645547617 is an apocalyptic number.

It is an amenable number.

645547617 is a deficient number, since it is larger than the sum of its proper divisors (478022943).

645547617 is a wasteful number, since it uses less digits than its factorization.

645547617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167230 (or 167224 counting only the distinct ones).

The product of its digits is 705600, while the sum is 45.

The square root of 645547617 is about 25407.6291101708. The cubic root of 645547617 is about 864.2567114306.

The spelling of 645547617 in words is "six hundred forty-five million, five hundred forty-seven thousand, six hundred seventeen".