645444033 has 16 divisors (see below), whose sum is σ = 927722880. Its totient is φ = 396797184.

The previous prime is 645444013. The next prime is 645444047. The reversal of 645444033 is 330444546.

It is not a de Polignac number, because 645444033 - 2⁹ = 645443521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645443985 and 645444003.

It is not an unprimeable number, because it can be changed into a prime (645444013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33673 + ... + 49241.

It is an arithmetic number, because the mean of its divisors is an integer number (57982680).

Almost surely, 2^645444033 is an apocalyptic number.

It is an amenable number.

645444033 is a deficient number, since it is larger than the sum of its proper divisors (282278847).

645444033 is a wasteful number, since it uses less digits than its factorization.

645444033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16648.

The product of its (nonzero) digits is 69120, while the sum is 33.

The square root of 645444033 is about 25405.5905855385. The cubic root of 645444033 is about 864.2104830019.

Adding to 645444033 its reverse (330444546), we get a palindrome (975888579).

The spelling of 645444033 in words is "six hundred forty-five million, four hundred forty-four thousand, thirty-three".