640546385 has 8 divisors (see below), whose sum is σ = 770872896. Its totient is φ = 510958960.

The previous prime is 640546363. The next prime is 640546477. The reversal of 640546385 is 583645046.

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

It is not a de Polignac number, because 640546385 - 2⁸ = 640546129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182861 + ... + 186330.

It is an arithmetic number, because the mean of its divisors is an integer number (96359112).

Almost surely, 2^640546385 is an apocalyptic number.

It is an amenable number.

640546385 is a deficient number, since it is larger than the sum of its proper divisors (130326511).

640546385 is a wasteful number, since it uses less digits than its factorization.

640546385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369543.

The product of its (nonzero) digits is 345600, while the sum is 41.

The square root of 640546385 is about 25309.0178592533. The cubic root of 640546385 is about 862.0190460062.

The spelling of 640546385 in words is "six hundred forty million, five hundred forty-six thousand, three hundred eighty-five".