65167219921 has 2 divisors, whose sum is σ = 65167219922. Its totient is φ = 65167219920.

The previous prime is 65167219919. The next prime is 65167219951. The reversal of 65167219921 is 12991276156.

It is a happy number.

65167219921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64853752896 + 313467025 = 254664^2 + 17705^2 .

It is a cyclic number.

It is not a de Polignac number, because 65167219921 - 2¹ = 65167219919 is a prime.

Together with 65167219919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (65167219951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32583609960 + 32583609961.

It is an arithmetic number, because the mean of its divisors is an integer number (32583609961).

Almost surely, 2^65167219921 is an apocalyptic number.

It is an amenable number.

65167219921 is a deficient number, since it is larger than the sum of its proper divisors (1).

65167219921 is an equidigital number, since it uses as much as digits as its factorization.

65167219921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 408240, while the sum is 49.

The spelling of 65167219921 in words is "sixty-five billion, one hundred sixty-seven million, two hundred nineteen thousand, nine hundred twenty-one".