645446851 has 8 divisors (see below), whose sum is σ = 738166784. Its totient is φ = 552855240.

The previous prime is 645446797. The next prime is 645446869. The reversal of 645446851 is 158644546.

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

It is not a de Polignac number, because 645446851 - 2⁹ = 645446339 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645446798 and 645446807.

It is not an unprimeable number, because it can be changed into a prime (645446951) 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, 21045 + ... + 41638.

It is an arithmetic number, because the mean of its divisors is an integer number (92270848).

Almost surely, 2^645446851 is an apocalyptic number.

645446851 is a deficient number, since it is larger than the sum of its proper divisors (92719933).

645446851 is a wasteful number, since it uses less digits than its factorization.

645446851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64161.

The product of its digits is 460800, while the sum is 43.

The square root of 645446851 is about 25405.6460457120. The cubic root of 645446851 is about 864.2117407106.

The spelling of 645446851 in words is "six hundred forty-five million, four hundred forty-six thousand, eight hundred fifty-one".