640567061 has 4 divisors (see below), whose sum is σ = 641138592. Its totient is φ = 639995532.

The previous prime is 640567033. The next prime is 640567069. The reversal of 640567061 is 160765046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640567061 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 (640567069) 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, 284081 + ... + 286326.

It is an arithmetic number, because the mean of its divisors is an integer number (160284648).

Almost surely, 2^640567061 is an apocalyptic number.

It is an amenable number.

640567061 is a deficient number, since it is larger than the sum of its proper divisors (571531).

640567061 is a wasteful number, since it uses less digits than its factorization.

640567061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571530.

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

The square root of 640567061 is about 25309.4263269636. The cubic root of 640567061 is about 862.0283208558.

It can be divided in two parts, 64056 and 7061, that added together give a palindrome (71117).

The spelling of 640567061 in words is "six hundred forty million, five hundred sixty-seven thousand, sixty-one".