645187883 has 4 divisors (see below), whose sum is σ = 679145160. Its totient is φ = 611230608.

The previous prime is 645187861. The next prime is 645187891. The reversal of 645187883 is 388781546.

645187883 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 388781546 = 2 ⋅194390773.

It is not a de Polignac number, because 645187883 - 2¹⁰ = 645186859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645187843) 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, 16978610 + ... + 16978647.

It is an arithmetic number, because the mean of its divisors is an integer number (169786290).

Almost surely, 2^645187883 is an apocalyptic number.

645187883 is a deficient number, since it is larger than the sum of its proper divisors (33957277).

645187883 is a wasteful number, since it uses less digits than its factorization.

645187883 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33957276.

The product of its digits is 1290240, while the sum is 50.

The square root of 645187883 is about 25400.5488720224. The cubic root of 645187883 is about 864.0961447613.

The spelling of 645187883 in words is "six hundred forty-five million, one hundred eighty-seven thousand, eight hundred eighty-three".