645144825 has 72 divisors (see below), whose sum is σ = 1205762112. Its totient is φ = 303663360.

The previous prime is 645144793. The next prime is 645144833. The reversal of 645144825 is 528441546.

It is a happy number.

It is not a de Polignac number, because 645144825 - 2⁵ = 645144793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 290419 + ... + 292631.

It is an arithmetic number, because the mean of its divisors is an integer number (16746696).

Almost surely, 2^645144825 is an apocalyptic number.

645144825 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

645144825 is a deficient number, since it is larger than the sum of its proper divisors (560617287).

645144825 is a wasteful number, since it uses less digits than its factorization.

645144825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2275 (or 2257 counting only the distinct ones).

The product of its digits is 153600, while the sum is 39.

The square root of 645144825 is about 25399.7012777710. The cubic root of 645144825 is about 864.0769218959.

The spelling of 645144825 in words is "six hundred forty-five million, one hundred forty-four thousand, eight hundred twenty-five".