640776487 has 8 divisors (see below), whose sum is σ = 690268320. Its totient is φ = 591313440.

The previous prime is 640776473. The next prime is 640776523. The reversal of 640776487 is 784677046.

640776487 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 640776487 - 2¹⁹ = 640252199 is a prime.

It is a super-2 number, since 2×640776487² = 821189012584122338, which contains 22 as substring.

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 640776487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640776467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68937 + ... + 77677.

It is an arithmetic number, because the mean of its divisors is an integer number (86283540).

Almost surely, 2^640776487 is an apocalyptic number.

640776487 is a deficient number, since it is larger than the sum of its proper divisors (49491833).

640776487 is a wasteful number, since it uses less digits than its factorization.

640776487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14393.

The product of its (nonzero) digits is 1580544, while the sum is 49.

The square root of 640776487 is about 25313.5633011238. The cubic root of 640776487 is about 862.1222540198.

The spelling of 640776487 in words is "six hundred forty million, seven hundred seventy-six thousand, four hundred eighty-seven".