68517287221 has 4 divisors (see below), whose sum is σ = 68698072000. Its totient is φ = 68336502444.

The previous prime is 68517287197. The next prime is 68517287231. The reversal of 68517287221 is 12278271586.

It is a happy number.

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 68517287221 - 2¹¹ = 68517285173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68517287231) 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, 90391821 + ... + 90392578.

It is an arithmetic number, because the mean of its divisors is an integer number (17174518000).

Almost surely, 2^68517287221 is an apocalyptic number.

It is an amenable number.

68517287221 is a deficient number, since it is larger than the sum of its proper divisors (180784779).

68517287221 is a wasteful number, since it uses less digits than its factorization.

68517287221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180784778.

The product of its digits is 752640, while the sum is 49.

The spelling of 68517287221 in words is "sixty-eight billion, five hundred seventeen million, two hundred eighty-seven thousand, two hundred twenty-one".