64365643565 has 16 divisors (see below), whose sum is σ = 79224318000. Its totient is φ = 50181860352.

The previous prime is 64365643561. The next prime is 64365643567. The reversal of 64365643565 is 56534656346.

It can be written as a sum of positive squares in 8 ways, for example, as 4615707721 + 59749935844 = 67939^2 + 244438^2 .

It is a cyclic number.

It is not a de Polignac number, because 64365643565 - 2² = 64365643561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64365643561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 775580 + ... + 854549.

It is an arithmetic number, because the mean of its divisors is an integer number (4951519875).

Almost surely, 2^64365643565 is an apocalyptic number.

It is an amenable number.

64365643565 is a deficient number, since it is larger than the sum of its proper divisors (14858674435).

64365643565 is a wasteful number, since it uses less digits than its factorization.

64365643565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630336.

The product of its digits is 23328000, while the sum is 53.

The spelling of 64365643565 in words is "sixty-four billion, three hundred sixty-five million, six hundred forty-three thousand, five hundred sixty-five".