640061567 has 4 divisors (see below), whose sum is σ = 647253360. Its totient is φ = 632869776.

The previous prime is 640061563. The next prime is 640061599. The reversal of 640061567 is 765160046.

640061567 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 640061567 - 2² = 640061563 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640061563) 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, 3595763 + ... + 3595940.

It is an arithmetic number, because the mean of its divisors is an integer number (161813340).

Almost surely, 2^640061567 is an apocalyptic number.

640061567 is a deficient number, since it is larger than the sum of its proper divisors (7191793).

640061567 is an equidigital number, since it uses as much as digits as its factorization.

640061567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7191792.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 640061567 is about 25299.4380767637. The cubic root of 640061567 is about 861.8015088935.

The spelling of 640061567 in words is "six hundred forty million, sixty-one thousand, five hundred sixty-seven".