81374776784 has 40 divisors (see below), whose sum is σ = 181781609280. Its totient is φ = 34566271488.

The previous prime is 81374776781. The next prime is 81374776787. The reversal of 81374776784 is 48767747318.

It is an interprime number because it is at equal distance from previous prime (81374776781) and next prime (81374776787).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81374776781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3202214 + ... + 3227525.

It is an arithmetic number, because the mean of its divisors is an integer number (4544540232).

Almost surely, 2^81374776784 is an apocalyptic number.

It is an amenable number.

81374776784 is an abundant number, since it is smaller than the sum of its proper divisors (100406832496).

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

81374776784 is a wasteful number, since it uses less digits than its factorization.

81374776784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6429867 (or 6429861 counting only the distinct ones).

The product of its digits is 44255232, while the sum is 62.

The spelling of 81374776784 in words is "eighty-one billion, three hundred seventy-four million, seven hundred seventy-six thousand, seven hundred eighty-four".