1216081423865 has 64 divisors (see below), whose sum is σ = 1823465336832. Its totient is φ = 756378604800.

The previous prime is 1216081423841. The next prime is 1216081423889. The reversal of 1216081423865 is 5683241806121.

It is an interprime number because it is at equal distance from previous prime (1216081423841) and next prime (1216081423889).

It is not a de Polignac number, because 1216081423865 - 2⁶ = 1216081423801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 433848554 + ... + 433851356.

It is an arithmetic number, because the mean of its divisors is an integer number (28491645888).

Almost surely, 2^{1216081423865} is an apocalyptic number.

It is an amenable number.

1216081423865 is a deficient number, since it is larger than the sum of its proper divisors (607383912967).

1216081423865 is a wasteful number, since it uses less digits than its factorization.

1216081423865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4950.

The product of its (nonzero) digits is 552960, while the sum is 47.

The spelling of 1216081423865 in words is "one trillion, two hundred sixteen billion, eighty-one million, four hundred twenty-three thousand, eight hundred sixty-five".