64745201665 has 4 divisors (see below), whose sum is σ = 77694242004. Its totient is φ = 51796161328.

The previous prime is 64745201663. The next prime is 64745201671. The reversal of 64745201665 is 56610254746.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14109401089 + 50635800576 = 118783^2 + 225024^2 .

It is a cyclic number.

It is not a de Polignac number, because 64745201665 - 2¹ = 64745201663 is a prime.

It is a super-2 number, since 2×64745201665² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64745201663) 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, 6474520162 + ... + 6474520171.

It is an arithmetic number, because the mean of its divisors is an integer number (19423560501).

Almost surely, 2^64745201665 is an apocalyptic number.

It is an amenable number.

64745201665 is a deficient number, since it is larger than the sum of its proper divisors (12949040339).

64745201665 is a wasteful number, since it uses less digits than its factorization.

64745201665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12949040338.

The product of its (nonzero) digits is 1209600, while the sum is 46.

The spelling of 64745201665 in words is "sixty-four billion, seven hundred forty-five million, two hundred one thousand, six hundred sixty-five".