645333421 has 8 divisors (see below), whose sum is σ = 648622080. Its totient is φ = 642051888.

The previous prime is 645333389. The next prime is 645333497. The reversal of 645333421 is 124333546.

645333421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645333421 - 2⁵ = 645333389 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 (645333721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 291300 + ... + 293506.

It is an arithmetic number, because the mean of its divisors is an integer number (81077760).

Almost surely, 2^645333421 is an apocalyptic number.

It is an amenable number.

645333421 is a deficient number, since it is larger than the sum of its proper divisors (3288659).

645333421 is a wasteful number, since it uses less digits than its factorization.

645333421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3563.

The product of its digits is 25920, while the sum is 31.

The square root of 645333421 is about 25403.4135698335. The cubic root of 645333421 is about 864.1611125912.

Adding to 645333421 its reverse (124333546), we get a palindrome (769666967).

The spelling of 645333421 in words is "six hundred forty-five million, three hundred thirty-three thousand, four hundred twenty-one".