65647617281 has 4 divisors (see below), whose sum is σ = 65650176000. Its totient is φ = 65645058564.

The previous prime is 65647617227. The next prime is 65647617319. The reversal of 65647617281 is 18271674656.

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 a de Polignac number, because none of the positive numbers 2^k-65647617281 is a prime.

It is a super-2 number, since 2×65647617281² (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 (65647617181) 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, 1240481 + ... + 1292318.

It is an arithmetic number, because the mean of its divisors is an integer number (16412544000).

Almost surely, 2^65647617281 is an apocalyptic number.

It is an amenable number.

65647617281 is a deficient number, since it is larger than the sum of its proper divisors (2558719).

65647617281 is a wasteful number, since it uses less digits than its factorization.

65647617281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2558718.

The product of its digits is 3386880, while the sum is 53.

The spelling of 65647617281 in words is "sixty-five billion, six hundred forty-seven million, six hundred seventeen thousand, two hundred eighty-one".