645459594025 has 9 divisors (see below), whose sum is σ = 800374877733. Its totient is φ = 516364461600.

The previous prime is 645459594023. The next prime is 645459594079. The reversal of 645459594025 is 520495954546.

The square root of 645459594025 is 803405.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 2441644569 + 643017949456 = 49413^2 + 801884^2 .

It is not a de Polignac number, because 645459594025 - 2¹ = 645459594023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645459594023) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3936685 + ... + 4097365.

Almost surely, 2^645459594025 is an apocalyptic number.

645459594025 is the 803405-th square number.

645459594025 is the 401703-rd centered octagonal number.

It is an amenable number.

645459594025 is a deficient number, since it is larger than the sum of its proper divisors (154915283708).

645459594025 is an frugal number, since it uses more digits than its factorization.

645459594025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321372 (or 160686 counting only the distinct ones).

The product of its (nonzero) digits is 38880000, while the sum is 58.

The spelling of 645459594025 in words is "six hundred forty-five billion, four hundred fifty-nine million, five hundred ninety-four thousand, twenty-five".