640785415 has 8 divisors (see below), whose sum is σ = 769396608. Its totient is φ = 512325600.

The previous prime is 640785367. The next prime is 640785449. The reversal of 640785415 is 514587046.

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

It is not a de Polignac number, because 640785415 - 2⁷ = 640785287 is a prime.

It is a Duffinian number.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 28311 + ... + 45640.

It is an arithmetic number, because the mean of its divisors is an integer number (96174576).

Almost surely, 2^640785415 is an apocalyptic number.

640785415 is a deficient number, since it is larger than the sum of its proper divisors (128611193).

640785415 is a wasteful number, since it uses less digits than its factorization.

640785415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75689.

The product of its (nonzero) digits is 134400, while the sum is 40.

The square root of 640785415 is about 25313.7396486572. The cubic root of 640785415 is about 862.1262580118.

The spelling of 640785415 in words is "six hundred forty million, seven hundred eighty-five thousand, four hundred fifteen".