640461113645 has 16 divisors (see below), whose sum is σ = 778925093040. Its totient is φ = 505490496000.

The previous prime is 640461113641. The next prime is 640461113657. The reversal of 640461113645 is 546311164046.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 53415529924 + 587045583721 = 231118^2 + 766189^2 .

It is not a de Polignac number, because 640461113645 - 2² = 640461113641 is a prime.

It is a super-3 number, since 3×640461113645³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640461113641) 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, 2114750 + ... + 2398559.

It is an arithmetic number, because the mean of its divisors is an integer number (48682818315).

Almost surely, 2^640461113645 is an apocalyptic number.

It is an amenable number.

640461113645 is a deficient number, since it is larger than the sum of its proper divisors (138463979395).

640461113645 is a wasteful number, since it uses less digits than its factorization.

640461113645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4513696.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 640461113645 in words is "six hundred forty billion, four hundred sixty-one million, one hundred thirteen thousand, six hundred forty-five".