65440327681 has 4 divisors (see below), whose sum is σ = 65671565872. Its totient is φ = 65209089492.

The previous prime is 65440327657. The next prime is 65440327691. The reversal of 65440327681 is 18672304456.

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 not a de Polignac number, because 65440327681 - 2¹¹ = 65440325633 is a prime.

It is a super-2 number, since 2×65440327681² (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 (65440327621) 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, 115618671 + ... + 115619236.

It is an arithmetic number, because the mean of its divisors is an integer number (16417891468).

Almost surely, 2^65440327681 is an apocalyptic number.

It is an amenable number.

65440327681 is a deficient number, since it is larger than the sum of its proper divisors (231238191).

65440327681 is a wasteful number, since it uses less digits than its factorization.

65440327681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231238190.

The product of its (nonzero) digits is 967680, while the sum is 46.

The spelling of 65440327681 in words is "sixty-five billion, four hundred forty million, three hundred twenty-seven thousand, six hundred eighty-one".