81763641216 has 128 divisors (see below), whose sum is σ = 249637860000. Its totient is φ = 26314702848.

The previous prime is 81763641173. The next prime is 81763641233. The reversal of 81763641216 is 61214636718.

81763641216 is a `hidden beast` number, since 8 + 1 + 7 + 636 + 4 + 1 + 2 + 1 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent 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, 307681 + ... + 508128.

Almost surely, 2^81763641216 is an apocalyptic number.

It is an amenable number.

81763641216 is an abundant number, since it is smaller than the sum of its proper divisors (167874218784).

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

81763641216 is a wasteful number, since it uses less digits than its factorization.

81763641216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815861 (or 815843 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The spelling of 81763641216 in words is "eighty-one billion, seven hundred sixty-three million, six hundred forty-one thousand, two hundred sixteen".