640467563 has 4 divisors (see below), whose sum is σ = 646808928. Its totient is φ = 634126200.

The previous prime is 640467559. The next prime is 640467629. The reversal of 640467563 is 365764046.

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

It is a cyclic number.

It is not a de Polignac number, because 640467563 - 2² = 640467559 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 640467563.

It is not an unprimeable number, because it can be changed into a prime (640467463) 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, 3170531 + ... + 3170732.

It is an arithmetic number, because the mean of its divisors is an integer number (161702232).

Almost surely, 2^640467563 is an apocalyptic number.

640467563 is a deficient number, since it is larger than the sum of its proper divisors (6341365).

640467563 is a wasteful number, since it uses less digits than its factorization.

640467563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6341364.

The product of its (nonzero) digits is 362880, while the sum is 41.

The square root of 640467563 is about 25307.4606193510. The cubic root of 640467563 is about 861.9836861665.

The spelling of 640467563 in words is "six hundred forty million, four hundred sixty-seven thousand, five hundred sixty-three".