645115453 has 4 divisors (see below), whose sum is σ = 645191260. Its totient is φ = 645039648.

The previous prime is 645115447. The next prime is 645115459. The reversal of 645115453 is 354511546.

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

It is an interprime number because it is at equal distance from previous prime (645115447) and next prime (645115459).

It can be written as a sum of positive squares in 2 ways, for example, as 424236409 + 220879044 = 20597^2 + 14862^2 .

It is a cyclic number.

It is not a de Polignac number, because 645115453 - 2⁵ = 645115421 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 (645115459) 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, 23250 + ... + 42787.

It is an arithmetic number, because the mean of its divisors is an integer number (161297815).

Almost surely, 2^645115453 is an apocalyptic number.

It is an amenable number.

645115453 is a deficient number, since it is larger than the sum of its proper divisors (75807).

645115453 is an equidigital number, since it uses as much as digits as its factorization.

645115453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75806.

The product of its digits is 36000, while the sum is 34.

The square root of 645115453 is about 25399.1230754135. The cubic root of 645115453 is about 864.0638085341.

Adding to 645115453 its reverse (354511546), we get a palindrome (999626999).

It can be divided in two parts, 6451 and 15453, that added together give a square (21904 = 148²).

The spelling of 645115453 in words is "six hundred forty-five million, one hundred fifteen thousand, four hundred fifty-three".