640071945 has 48 divisors (see below), whose sum is σ = 1160894592. Its totient is φ = 325628160.

The previous prime is 640071923. The next prime is 640071953. The reversal of 640071945 is 549170046.

640071945 is a `hidden beast` number, since 640 + 0 + 7 + 1 + 9 + 4 + 5 = 666.

It is not a de Polignac number, because 640071945 - 2⁹ = 640071433 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 538642 + ... + 539828.

It is an arithmetic number, because the mean of its divisors is an integer number (24185304).

Almost surely, 2^640071945 is an apocalyptic number.

It is an amenable number.

640071945 is a deficient number, since it is larger than the sum of its proper divisors (520822647).

640071945 is a wasteful number, since it uses less digits than its factorization.

640071945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742 (or 1739 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 640071945 is about 25299.6431793020. The cubic root of 640071945 is about 861.8061666369.

The spelling of 640071945 in words is "six hundred forty million, seventy-one thousand, nine hundred forty-five".