81195781782 has 32 divisors (see below), whose sum is σ = 163245732192. Its totient is φ = 26923221504.

The previous prime is 81195781697. The next prime is 81195781789. The reversal of 81195781782 is 28718759118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81195781789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 978958 + ... + 1058654.

It is an arithmetic number, because the mean of its divisors is an integer number (5101429131).

Almost surely, 2^81195781782 is an apocalyptic number.

81195781782 is an abundant number, since it is smaller than the sum of its proper divisors (82049950410).

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

81195781782 is a wasteful number, since it uses less digits than its factorization.

81195781782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80592.

The product of its digits is 2257920, while the sum is 57.

The spelling of 81195781782 in words is "eighty-one billion, one hundred ninety-five million, seven hundred eighty-one thousand, seven hundred eighty-two".