640834741 has 4 divisors (see below), whose sum is σ = 641015532. Its totient is φ = 640653952.

The previous prime is 640834739. The next prime is 640834757. The reversal of 640834741 is 147438046.

640834741 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 141491025 + 499343716 = 11895^2 + 22346^2 .

It is a cyclic number.

It is not a de Polignac number, because 640834741 - 2¹ = 640834739 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640834741.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640834781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84970 + ... + 92203.

It is an arithmetic number, because the mean of its divisors is an integer number (160253883).

Almost surely, 2^640834741 is an apocalyptic number.

It is an amenable number.

640834741 is a deficient number, since it is larger than the sum of its proper divisors (180791).

640834741 is a wasteful number, since it uses less digits than its factorization.

640834741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180790.

The product of its (nonzero) digits is 64512, while the sum is 37.

The square root of 640834741 is about 25314.7139229342. The cubic root of 640834741 is about 862.1483788590.

The spelling of 640834741 in words is "six hundred forty million, eight hundred thirty-four thousand, seven hundred forty-one".