81344111616 has 66 divisors (see below), whose sum is σ = 234879383622. Its totient is φ = 27114700800.

The previous prime is 81344111603. The next prime is 81344111657. The reversal of 81344111616 is 61611144318.

81344111616 is a `hidden beast` number, since 8 + 1 + 34 + 4 + 1 + 1 + 1 + 616 = 666.

It can be written as a sum of positive squares in only one way, i.e., 76229001216 + 5115110400 = 276096^2 + 71520^2 .

It is a super-2 number, since 2×81344111616² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4403985 + ... + 4422416.

Almost surely, 2^81344111616 is an apocalyptic number.

It is an amenable number.

81344111616 is an abundant number, since it is smaller than the sum of its proper divisors (153535272006).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81344111616 is a wasteful number, since it uses less digits than its factorization.

81344111616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8826427 (or 8826406 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The spelling of 81344111616 in words is "eighty-one billion, three hundred forty-four million, one hundred eleven thousand, six hundred sixteen".