645531053 has 4 divisors (see below), whose sum is σ = 646002588. Its totient is φ = 645059520.

The previous prime is 645531017. The next prime is 645531071. The reversal of 645531053 is 350135546.

645531053 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 626851369 + 18679684 = 25037^2 + 4322^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645531053 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 (645531013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233708 + ... + 236453.

It is an arithmetic number, because the mean of its divisors is an integer number (161500647).

Almost surely, 2^645531053 is an apocalyptic number.

It is an amenable number.

645531053 is a deficient number, since it is larger than the sum of its proper divisors (471535).

645531053 is a wasteful number, since it uses less digits than its factorization.

645531053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471534.

The product of its (nonzero) digits is 27000, while the sum is 32.

The square root of 645531053 is about 25407.3031429941. The cubic root of 645531053 is about 864.2493194272.

Adding to 645531053 its reverse (350135546), we get a palindrome (995666599).

The spelling of 645531053 in words is "six hundred forty-five million, five hundred thirty-one thousand, fifty-three".