645428255 has 4 divisors (see below), whose sum is σ = 774513912. Its totient is φ = 516342600.

The previous prime is 645428249. The next prime is 645428257. The reversal of 645428255 is 552824546.

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

It is not a de Polignac number, because 645428255 - 2⁸ = 645427999 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 (645428257) 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, 64542821 + ... + 64542830.

It is an arithmetic number, because the mean of its divisors is an integer number (193628478).

Almost surely, 2^645428255 is an apocalyptic number.

645428255 is a deficient number, since it is larger than the sum of its proper divisors (129085657).

645428255 is a wasteful number, since it uses less digits than its factorization.

645428255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129085656.

The product of its digits is 384000, while the sum is 41.

The square root of 645428255 is about 25405.2800614360. The cubic root of 645428255 is about 864.2034410156.

The spelling of 645428255 in words is "six hundred forty-five million, four hundred twenty-eight thousand, two hundred fifty-five".