645645447 has 6 divisors (see below), whose sum is σ = 932598992. Its totient is φ = 430430292.

The previous prime is 645645391. The next prime is 645645457. The reversal of 645645447 is 744546546.

645645447 is a `hidden beast` number, since 6 + 45 + 64 + 544 + 7 = 666.

It is not a de Polignac number, because 645645447 - 2¹⁰ = 645644423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645645457) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35869183 + ... + 35869200.

Almost surely, 2^645645447 is an apocalyptic number.

645645447 is a deficient number, since it is larger than the sum of its proper divisors (286953545).

645645447 is a wasteful number, since it uses less digits than its factorization.

645645447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71738389 (or 71738386 counting only the distinct ones).

The product of its digits is 1612800, while the sum is 45.

The square root of 645645447 is about 25409.5542463854. The cubic root of 645645447 is about 864.3003673702.

The spelling of 645645447 in words is "six hundred forty-five million, six hundred forty-five thousand, four hundred forty-seven".