78216325367721 has 4 divisors (see below), whose sum is σ = 104288433823632. Its totient is φ = 52144216911812.

The previous prime is 78216325367717. The next prime is 78216325367771. The reversal of 78216325367721 is 12776352361287.

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 78216325367721 - 2² = 78216325367717 is a prime.

It is a super-2 number, since 2×78216325367721² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78216325367771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13036054227951 + ... + 13036054227956.

It is an arithmetic number, because the mean of its divisors is an integer number (26072108455908).

Almost surely, 2^{78216325367721} is an apocalyptic number.

It is an amenable number.

78216325367721 is a deficient number, since it is larger than the sum of its proper divisors (26072108455911).

78216325367721 is a wasteful number, since it uses less digits than its factorization.

78216325367721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26072108455910.

The product of its digits is 35562240, while the sum is 60.

The spelling of 78216325367721 in words is "seventy-eight trillion, two hundred sixteen billion, three hundred twenty-five million, three hundred sixty-seven thousand, seven hundred twenty-one".