640777594 has 8 divisors (see below), whose sum is σ = 961304148. Its totient is φ = 320342880.

The previous prime is 640777567. The next prime is 640777597. The reversal of 640777594 is 495777046.

It can be written as a sum of positive squares in 2 ways, for example, as 583850569 + 56927025 = 24163^2 + 7545^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (640777597) 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 3 ways as a sum of consecutive naturals, for example, 1507 + ... + 35830.

Almost surely, 2^640777594 is an apocalyptic number.

640777594 is a deficient number, since it is larger than the sum of its proper divisors (320526554).

640777594 is a wasteful number, since it uses less digits than its factorization.

640777594 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45920.

The product of its (nonzero) digits is 1481760, while the sum is 49.

The square root of 640777594 is about 25313.5851668625. The cubic root of 640777594 is about 862.1227504846.

The spelling of 640777594 in words is "six hundred forty million, seven hundred seventy-seven thousand, five hundred ninety-four".