645546353 has 4 divisors (see below), whose sum is σ = 661291428. Its totient is φ = 629801280.

The previous prime is 645546331. The next prime is 645546371. The reversal of 645546353 is 353645546.

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 393149584 + 252396769 = 19828^2 + 15887^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645546353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 15745033 = 645546353 / (6 + 4 + 5 + 5 + 4 + 6 + 3 + 5 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645546353.

It is not an unprimeable number, because it can be changed into a prime (645546053) 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, 7872476 + ... + 7872557.

It is an arithmetic number, because the mean of its divisors is an integer number (165322857).

Almost surely, 2^645546353 is an apocalyptic number.

It is an amenable number.

645546353 is a deficient number, since it is larger than the sum of its proper divisors (15745075).

645546353 is a wasteful number, since it uses less digits than its factorization.

645546353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15745074.

The product of its digits is 648000, while the sum is 41.

The square root of 645546353 is about 25407.6042357401. The cubic root of 645546353 is about 864.2561473508.

It can be divided in two parts, 64554 and 6353, that added together give a palindrome (70907).

The spelling of 645546353 in words is "six hundred forty-five million, five hundred forty-six thousand, three hundred fifty-three".