645503453 has 4 divisors (see below), whose sum is σ = 737718240. Its totient is φ = 553288668.

The previous prime is 645503381. The next prime is 645503471. The reversal of 645503453 is 354305546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645503453 - 2⁸ = 645503197 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645503153) 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, 46107383 + ... + 46107396.

It is an arithmetic number, because the mean of its divisors is an integer number (184429560).

Almost surely, 2^645503453 is an apocalyptic number.

It is an amenable number.

645503453 is a deficient number, since it is larger than the sum of its proper divisors (92214787).

645503453 is an equidigital number, since it uses as much as digits as its factorization.

645503453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92214786.

The product of its (nonzero) digits is 108000, while the sum is 35.

The square root of 645503453 is about 25406.7599862714. The cubic root of 645503453 is about 864.2370021157.

Adding to 645503453 its reverse (354305546), we get a palindrome (999808999).

The spelling of 645503453 in words is "six hundred forty-five million, five hundred three thousand, four hundred fifty-three".