64965145681 has 8 divisors (see below), whose sum is σ = 65222585064. Its totient is φ = 64708089600.

The previous prime is 64965145643. The next prime is 64965145727. The reversal of 64965145681 is 18654156946.

It can be written as a sum of positive squares in 4 ways, for example, as 184715281 + 64780430400 = 13591^2 + 254520^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64965145681 - 2¹⁵ = 64965112913 is a prime.

It is a super-2 number, since 2×64965145681² (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 (64965145631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246231 + ... + 436531.

It is an arithmetic number, because the mean of its divisors is an integer number (8152823133).

Almost surely, 2^64965145681 is an apocalyptic number.

It is an amenable number.

64965145681 is a deficient number, since it is larger than the sum of its proper divisors (257439383).

64965145681 is a wasteful number, since it uses less digits than its factorization.

64965145681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191651.

The product of its digits is 6220800, while the sum is 55.

The spelling of 64965145681 in words is "sixty-four billion, nine hundred sixty-five million, one hundred forty-five thousand, six hundred eighty-one".