81776342772 has 96 divisors (see below), whose sum is σ = 224980761600. Its totient is φ = 25631644896.

The previous prime is 81776342719. The next prime is 81776342773. The reversal of 81776342772 is 27724367718.

81776342772 is a `hidden beast` number, since 81 + 7 + 76 + 3 + 427 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81776342773) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 132438 + ... + 425549.

It is an arithmetic number, because the mean of its divisors is an integer number (2343549600).

Almost surely, 2^81776342772 is an apocalyptic number.

It is an amenable number.

81776342772 is an abundant number, since it is smaller than the sum of its proper divisors (143204418828).

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

81776342772 is a wasteful number, since it uses less digits than its factorization.

81776342772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558082 (or 558074 counting only the distinct ones).

The product of its digits is 5531904, while the sum is 54.

The spelling of 81776342772 in words is "eighty-one billion, seven hundred seventy-six million, three hundred forty-two thousand, seven hundred seventy-two".