645387783546 has 32 divisors (see below), whose sum is σ = 1440865755648. Its totient is φ = 191023867440.

The previous prime is 645387783541. The next prime is 645387783571.

645387783546 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is not an unprimeable number, because it can be changed into a prime (645387783541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113701846 + ... + 113707521.

It is an arithmetic number, because the mean of its divisors is an integer number (45027054864).

Almost surely, 2^645387783546 is an apocalyptic number.

645387783546 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

645387783546 is an abundant number, since it is smaller than the sum of its proper divisors (795477972102).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645387783546 is a wasteful number, since it uses less digits than its factorization.

645387783546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227409426.

The product of its digits is 406425600, while the sum is 66.

The spelling of 645387783546 in words is "six hundred forty-five billion, three hundred eighty-seven million, seven hundred eighty-three thousand, five hundred forty-six".