1216455722065 has 16 divisors (see below), whose sum is σ = 1581558853248. Its totient is φ = 894619143936.

The previous prime is 1216455722057. The next prime is 1216455722089. The reversal of 1216455722065 is 5602275546121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1216455722065 - 2³ = 1216455722057 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166406157 + ... + 166413466.

It is an arithmetic number, because the mean of its divisors is an integer number (98847428328).

Almost surely, 2^{1216455722065} is an apocalyptic number.

It is an amenable number.

1216455722065 is a deficient number, since it is larger than the sum of its proper divisors (365103131183).

1216455722065 is a wasteful number, since it uses less digits than its factorization.

1216455722065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332819688.

The product of its (nonzero) digits is 1008000, while the sum is 46.

The spelling of 1216455722065 in words is "one trillion, two hundred sixteen billion, four hundred fifty-five million, seven hundred twenty-two thousand, sixty-five".