65440764591 has 4 divisors (see below), whose sum is σ = 87254352792. Its totient is φ = 43627176392.

The previous prime is 65440764577. The next prime is 65440764629. The reversal of 65440764591 is 19546704456.

It is a happy number.

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 65440764591 - 2⁶ = 65440764527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65440764491) 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, 10906794096 + ... + 10906794101.

It is an arithmetic number, because the mean of its divisors is an integer number (21813588198).

Almost surely, 2^65440764591 is an apocalyptic number.

65440764591 is a deficient number, since it is larger than the sum of its proper divisors (21813588201).

65440764591 is a wasteful number, since it uses less digits than its factorization.

65440764591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21813588200.

The product of its (nonzero) digits is 3628800, while the sum is 51.

The spelling of 65440764591 in words is "sixty-five billion, four hundred forty million, seven hundred sixty-four thousand, five hundred ninety-one".