645551063504 has 40 divisors (see below), whose sum is σ = 1265872137480. Its totient is φ = 318880483328.

The previous prime is 645551063431. The next prime is 645551063513. The reversal of 645551063504 is 405360155546.

It can be written as a sum of positive squares in 4 ways, for example, as 51233417104 + 594317646400 = 226348^2 + 770920^2 .

It is a super-2 number, since 2×645551063504² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1508834 + ... + 1888830.

It is an arithmetic number, because the mean of its divisors is an integer number (31646803437).

Almost surely, 2^645551063504 is an apocalyptic number.

It is an amenable number.

645551063504 is a deficient number, since it is larger than the sum of its proper divisors (620321073976).

645551063504 is a wasteful number, since it uses less digits than its factorization.

645551063504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381287 (or 381281 counting only the distinct ones).

The product of its (nonzero) digits is 1080000, while the sum is 44.

The spelling of 645551063504 in words is "six hundred forty-five billion, five hundred fifty-one million, sixty-three thousand, five hundred four".