642746565 has 24 divisors (see below), whose sum is σ = 1114741368. Its totient is φ = 342599040.

The previous prime is 642746521. The next prime is 642746567. The reversal of 642746565 is 565647246.

642746565 is a `hidden beast` number, since 6 + 42 + 7 + 46 + 565 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 186240609 + 456505956 = 13647^2 + 21366^2 .

It is not a de Polignac number, because 642746565 - 2⁸ = 642746309 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 642746565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642746567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106735 + ... + 112595.

It is an arithmetic number, because the mean of its divisors is an integer number (46447557).

Almost surely, 2^642746565 is an apocalyptic number.

It is an amenable number.

642746565 is a deficient number, since it is larger than the sum of its proper divisors (471994803).

642746565 is a wasteful number, since it uses less digits than its factorization.

642746565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8309 (or 8306 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 45.

The square root of 642746565 is about 25352.4469233248. The cubic root of 642746565 is about 863.0048864987.

The spelling of 642746565 in words is "six hundred forty-two million, seven hundred forty-six thousand, five hundred sixty-five".