645548778013 has 16 divisors (see below), whose sum is σ = 654328840000. Its totient is φ = 636844602240.

The previous prime is 645548777989. The next prime is 645548778053. The reversal of 645548778013 is 310877845546.

It is a cyclic number.

It is not a de Polignac number, because 645548778013 - 2⁹ = 645548777501 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 (645548778053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12329113 + ... + 12381361.

It is an arithmetic number, because the mean of its divisors is an integer number (40895552500).

Almost surely, 2^645548778013 is an apocalyptic number.

It is an amenable number.

645548778013 is a deficient number, since it is larger than the sum of its proper divisors (8780061987).

645548778013 is a wasteful number, since it uses less digits than its factorization.

645548778013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52972.

The product of its (nonzero) digits is 22579200, while the sum is 58.

The spelling of 645548778013 in words is "six hundred forty-five billion, five hundred forty-eight million, seven hundred seventy-eight thousand, thirteen".