640512734 has 16 divisors (see below), whose sum is σ = 998298000. Its totient is φ = 307844544.

The previous prime is 640512721. The next prime is 640512739. The reversal of 640512734 is 437215046.

It is a self number, because there is not a number n which added to its sum of digits gives 640512734.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640512739) 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 7 ways as a sum of consecutive naturals, for example, 11159 + ... + 37490.

It is an arithmetic number, because the mean of its divisors is an integer number (62393625).

Almost surely, 2^640512734 is an apocalyptic number.

640512734 is a deficient number, since it is larger than the sum of its proper divisors (357785266).

640512734 is a wasteful number, since it uses less digits than its factorization.

640512734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48907.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 640512734 is about 25308.3530479563. The cubic root of 640512734 is about 862.0039503985.

The spelling of 640512734 in words is "six hundred forty million, five hundred twelve thousand, seven hundred thirty-four".